Homemade RO

[jrgagne99]

I'm guess I'm going to be the latest one to try to cobble together a homemade RO. Now don't laugh... I'm going to try using two 100 gpd residential tapwater membranes (M-T1812A100, $26 each at www.watereverywhere.com), running in paralell. For 77F tapwater at 50 psi, they are rated for 100 gpd permeate, with a 3:1 concentrate to permeate ratio (not very good at first glance). Further, at 40F the permeate flow will be cut at least in half. But I hope to compensate (completely?) by running them at 100 psi instead of 50 (they are rated to 120 psi). Of course, the permeate flowrate will be slower than advertised, since 2% sap has much more TDS (20,000 ppm I think?) than even the dirtiest tap water for which these membranes are rated (2000 TDS). But the guys who tried the Merlin a couple years ago (Brent et al.) seemed to be getting about 25% of the advertised permeate flow through the Merlins when running sap. I'm hoping for similar performance from these membranes as well. So running two 100 gpd membranes, I hope to get about 50 gpd of permeate. That's 50 gpd I won't need to boil--- a big difference for my 100 tap operation, especially since I'm over 90% red maples, currently coming in at 1.6%.

So my plan is to supply the 100 gpd in parallel with a Aquatec 8800 series booster pump at 15 gph/100 psi. I'll run 5 micron and 1 micron prefilters. I might try a preheater as well to increase flowrates a bit, since I'll probably be dumping concentrate right back into my bulk collection tank (which is nice and cold).

Total system from wateranywhere.com:
2 x Housing for Residential Membrane, IN: st., OUT: el. (PV2012PME) = $21.00
2 x 100 Gallon Per Day Residential RO Membrane (M-T1812A100) = $53.00
1 x Aquatec Booster Pump 50-100 GPD (8851-2J03-B423) = $90.00
1 x Power Supply for Aquatec 50-100 GPD, 115-120v/60Hz, USA (TACS114-48) = $27.00
2 x 10" Standard Filter Housing, Clear/White, 1/4" in/out (H-H14XCE33) = $25.00
2 x 10" 1 Micron Sediment Filters Polyspun (H-F1001CF) = $6.00
2 x 10" 5 Micron Sediment Filters Polyspun (H-F1005CF) = $6.00
United Parcel Service (1 x 24.442lbs) (Ground): $34.69
Sub-Total: $228.00
Total: $262.69

Here's to hoping it will work out!

[jrgagne99]

Just ordered all of the parts today, and I can't wait until they come in so I can start putting this together. I'll need to figure out how to flush/wash these membranes once I get everything up and going. Does anyone have any pointers on this?

[500592]

When you start you should post some pics or drawings of what your doing

[PapaSmiff]

I'm very interested to see how this works out for you. I need a low-cost RO system, if I'm going to ramp up to 100 taps within a couple years. Also, if you put together a diagram for this, would you be willing to share it?

Will you have an opportunity to try it out this year? My season is going to be over in about a week (or less).

Good Luck!

[jrgagne99]

Here is the basic schematic I'll be working from. We're only two weeks into the season in central NH, so hopefully I'll have a chance to test it this year.

[Gary in NH]

The Aquatec 8800 booster pump has a 125 psi maximum rating based on feeding it with a pressurized supply. At a 0 psi feed it will boost pressure to 80 psi @ 1 GPM. If flow is more than 1 GPM the pressure will drop off as flow increases. Do you know what rating the capillary tubes are for drain (concentrate) flow for each membrane? They are usually rated in ml/minute. To convert that to a GPD number multiply ml/min rating X .3985 to get the GPD flow so you can work with all GPD numbers. If the flow through both membranes is too high in parallel you could try going to a series set up feeding the 2nd membrane with the concentrate from the first which will also give you a higher sugar content. Swap the membrane postions on an equal time line to balance out which one sees raw and which one sees concentrated sap. I wouldn't bother cleaning them with anything besides long warm water rinse after you're done. They aren't going to see enough sap or high enough sugar content to cause a problem. The TDS will also not be a problem. Sap has a TDS of 150 to 200 mg/l so even if you run it through a couple of times to concentrate to 10% it will barely get to 600 mg/l. From a design standpoint you may have been thinking of what is known as "osmotic back pressure" which is related to the mineral content in feed liquid. For every 100 mg/l of TDS it takes 1 psi of net driving force applied to the membrane to get the liquid moving or "reverse osmosis". So at 150 mg/l of TDS in sap you will lose 1.5 psi of net driving pressure across the membrane before you get any flow and rejection by the membrane. It's a pretty small number and inconsequential for a sap RO. If the RO was being used to desalinate seawater which has a TDS of +/-30,000 mg/l it would be significant since you would have an osmotic back pressure of 300 psi to deal with. After crunching the numbers this RO may help you out a little bit but I think it's going to be a very slow process and you will still be evaporating a majority of your sap. You have most of the components needed for a good residential RO drinking water system though. Add a storage tank, a faucet, a pressure switch and solenoid and you'll be all set.

[jrgagne99]

"Do you know what rating the capillary tubes are for drain (concentrate) flow for each membrane?"

Not exactly. Supposedly, it's a 100 GPD membrane intended to be used with a 3:1 (concentrate to permeate) restrictor. This implies 300 gpd "concentrate" (I use the word loosely) for a capillary tube rating of 750 mL/min. Are the capillary tubes integrated in the membrane itself? I don't quite understand how this could be, since the high pressure side of the membrane is around its OD and the product (permeate) is coming out the tube centered on the ID. Seems like any concentrate flow restrictions would need to be built into the membrane housing... Regardless, I was planning to add my own control valve flow restriction downstream of the housing concentrate ports to control the permeate flow and therefore, membrane delta-P (up to limit of the pump recirc setting (110 psi I think). I think that if I didn't have a control valve downstream of the membrane, I wouldn't be able to achieve the higher membrane pressure drop that I desire.

BTW, the Aquatec is rated at 1.2 liters/min at 80 psi. That converts to about 470 GPD. So I may end up running the membranes in series since with a 3:1 ratio I'll need to supply about 400 GPD per membrane. But I anticipate that the flows will be somewhat reduced for sap, relative to tapwater. Or I may try to crank the ratio down to 2:1 or less, in order to reduce the flow so that the pump can keep up.

Also- Thanks Gary for the insights on membrane cleaning and the TDS numbers for sap. I now understand why my 20,000 ppm was wrong: 2% solution means 2% by mass. So that equates to about 200 mg/L of water, TDS. Since a sucrose molecule is about 20x more massive than a water molecule, my original calculation of 20,000 ppm should be corrected to 1000 ppm TDS.

[Gary in NH]

The capillary tube is usually inserted into the drain line tubing or depending on the pressure vessel there may be a port for one in the end cap. It is a rubber grommet with a very thin tube that fits into the end of the concentrate line tubing and serves as a flow restrictor. Some have screens over them to keep out small particles which can clog them. Various flow rates are determined by the diameter of the tubing and the length. Many manufacturers color code them because it hard to tell one from another. If you buy them as a part they usually come 12" to 16" long and you trim them to length to get the desired concentrate flow. Shortening the length results in a faster concentrate flow. Regulating the concentrate flow with an adjustable valve will be very difficult at the such a low flow rate which is why the capillary tubes are used. A needle valve is your best bet if you are going to try to regulate the concentrate flow. You are correct, the Aquatec is 1.2 LPM, not GPM. Figure a little less than half the rated membrane output for the permeate side with sap at 43 degrees F. As the sap gets warmer it will go through to the permeate side faster. The TDS readings I'm referring to only apply to minerals in the sap (or water). What is being measured by a TDS meter is the conductivity or its reciprocal, resistivity of the minerals in solution. Minerals in water (or sap) will conduct electrical current and a TDS meter is estimating the mineral content based on the conductivity. Sugars are organic and do not conduct electricity so they would not be read by a TDS meter. I've only thought of the sugar content as a percentage of the sap volume based on my sap hydrometer. I see where your coming from with your calculations, mg/l is a weight to weight ratio. You probably already know this if you've done the math - parts per million (ppm) and milligrams per liter (mg/l) are the same thing. I really do hope your RO experiment works out for you. The members on this site have proved invaluable to me for providing information that would have taken me years to figure out on my own by trial and error. I was trying to do the same by sharing the RO info since I had also experimented with a similar set-up a few years ago. Good luck this weekend !!

[Kev]

thanks Gary and JR
you just explained some stuff that I was not sure how I wanted to try to phrase the question for.

[jrgagne99]

I assembled the system and did my first tests last night. In summary, I'm getting about 3-4 gph of permeate (effective evaporation) from the unit. This was running ~38F sap at 95 psi. Concentrated from 1.6% (soft maples) to 2.5% in one pass. I could probably do a little better by increaseing the flow restrictors on the concentrate lines. Right now I'm using a 50 gpd capillary tube to provide the back pressure to the membrane. I'm getting about a 3:1 concentrate to permeate ratio. The 3-4 gph works out to 70-100 gpd of effective evaporation. Now I need to figure out the best way of running continuously (e.g. overnight), which will probably be to run the system in my basement. I didn't run it overnight last night for fear of freezing- I brought it inside instead. Does anyone know if freezing the residential membranes is a problem? Also, I flushed with 10 gallons of permeate before bringing it in last night. Is this the recommended approach, or should I do some kind of back-flushing, like pushing permeate back through the membrane from the low-pressure side? So far I'm pretty pleased with the unit.

I'm thinking about tee-ing the inlet of the RO to the outlet of my copper-coil stove-pipe heat exchanger (sap is heated to about 70F in this coil) to increase the RO's permeate flowrate during boiling. I could run it like this during boiling and just cycline the concentrate back into my evaporator feeder tank.

[jludman]

Very nice. Did you end up needing to run to a hardware store, or did your original shopping list work? Picture of the setup?

[jrgagne99]

I only had to make one run to the hardware store to adapt from 3/8" tubing from the pump to the 1/4" I tubing used in the rest of the system. I didn't take any pictures last night, I'll post pictures on Monday...

One thing that I noticed is that when my raw sap bucket got low enough for the pump to take a gulp of air, the pump was unable to recover its full pressure ability without a little convincing. I had to remove the outlet line from the QC pump outlet fitting, run the pump for a couple of seconds, turn it off, then plug the outlet line back into the QC fitting. Kind of an air purge cycle I guess... Not a big deal, but I wouldn't want to do this very often. Does anyone know what might be going on in this case? It is a diaphragm pump, if that matters.

[Gary in NH]

Freezing any membrane is a problem, don't let it freeze or it could be damaged. The only exception would be for membranes that are in their original bags from the manufacturer and have not yet been wet in a system. Don't run any water pressure backwards from the permeate side to the concentrate side to flush, that will damage the membrane as well. An end of the day fresh water rinse is fine. You may want to take out the capillary tube and flush it a higher flow rate. More flow across the concentrate side of the membrane will rinse it quicker. As you start to flush with water continue to collect the concentrate until the sugar level drops. I check mine with my sap hydrometer. You will be surprised how much sugar continues to come out before its flushing with just water. When I start I also run the first couple of gallons of concentrate back to the sap tank until it's sweet. How many times will you run the sap through the RO? I would be concerned about it warming up and going bad if it sits around too long between passes through the RO. I'm not sure how you're getting over a 50% increase in sugar by removing 25% to 30% as permeate.

[Kev]

Gary
Do you leave the cap tube in place untill the sugar content drops?
or do you pull it right a way and still get a substancial amount of concentrate as you begin the flush cycle?

[Gary in NH]

I have throttling valves and I leave the concentrate flow adjustment alone. I shut down the RO and sap pump when the sap tank is almost empty then hook up a soft water feed to the RO. I restart without the sap pump because my well runs 50-70 psi. I re-adjust the system pressure back to 250 psi and run the concentrate to a tall graduated cylinder with my sap hydrometer in it. When the sugar content goes back down to around 3% I stop collecting the concentrate and let both permeate and concentrate go to drain (dry well). I re-adjust concentrate stream to twice the flow of permeate and let it flush for a 1/2 hour or so. Also VERY IMPORTANT if you're doing a small RO to throw out the pre-filter(s) before you rinse. I take the filter out and rinse the sump then I rinse the RO without one in the housing. You will not be able to flush out all the sugar from the filter in the housing and it will develop an off taste and odor as it sits idle after rinsing.

[Kev]

thanks Gary
great info.

[jrgagne99]

I ran the RO most of the weekend with pretty good success. I'm averaging about 3.5 gph of permeate. My ratio is about 4:1 (concentrate to permeate), but I haven't been keeping tabs on that since I set up the RO to cycle the sap in my 180 gallon stock tank. I also haven't been keeping a close watch on the sugar content of the concentrate, since I'm just recycling it back into my well-chilled (burried in a snow-bank) stock tank. Permeate checks out at 0% though. To try to pull in the less concentrated sap to the RO, (I'm currently getting about 3.7 gph permeate on 1.6% raw sap vs 3.2 gph for one-pass 2.5% concentrate) I use a float on my intake line so that I'm pulling in raw sap off the top of the tank. In theory this is where the lighter less concentrated sap should be. I sunk the end of the concentrate output line to the bottom of the tank so that I'm putting the heavier concentrated sap back into the tank at the bottom. I'm not sure if this makes much difference since natural diffusion may be mixing it all up anyway, but I figured it couldn't hurt.


I'm going to try adding two more membranes in parallel for a total of four to increase my permeate flow-rate. The membrane housings are only $10 and the 100 GPD membranes are $26 at wateranywhere.com. They also have 150 GPD membranes ($28) that I might try next year. Since I'm getting about a 4:1 concentrate to permeate ratio with two membranes, adding two more membranes in parallel should bump my ratio up to 4:2. That's only 20% more flow work for the pump, so I think it can handle it.

I mounted the RO to a plywood frame so that I could bring it in at night to avoid freezing. Need to figure out something better for next year (run it in my basement?). I posted a couple pictures of my setup. The first picture is a close-up of the RO unit. You can see the pump, the 5 and 1 um filters, the two membranes, the permeate flowmeter, the membrane pressure gauge and the capillary tube cartridge. The other picture shows my entire collection setup, including my 2.5 cfm vacuum pump and my homemade releaser. I consistently get 22 inHg from this system and all the sap I can handle on my 20"x40" homemade drop-flue.

[jrgagne99]

I forgot to mention my rinse strategy. I cycled permeate through for 2 hours after each 12-hour run. I observed an almost immediate increase in the permeate flow during the rinse cycle, and a corresponding drop in the membrane pressure. But I ran it for 2 hours anyway just to give it a good rinse. I should probably use warm water though, right now I'm just using my cold permeate.

Gary- Thanks for the tip about replacing the filters. I haven't taken them out yet. I think they are getting well rinsed in the rinse cycle, but you never can be too careful. Besides, they are only a few dollars each for the polyspun variety. I did discover on my own your tips about pouring the beginning of the rinsate back into my sap tank until it looses its sweetness. Correspondingly, dumping the concentrate onto the ground during subsequent startup until it begins to sweeten.

I think the 4:1 numbers make reasonable sense for sweeting from 1.6% to 2.5% in one pass, considering the accuracy of my measurements. For example: Let's say I start with 100 gallons of 1.6% This means I have 1.6 "gallons of sugar" dissolved in 98.4 gallons of water (I put "gallons of sugar" in quotes because sugar content is actually measured by mass not volume, but for this dilute example it should be close enough). With a 4:1 concentration to permeate ratio, I would remove 20 gallons of water on one pass leaving 1.6 "gallons of sugar" and 78.4 gallons of water. This is a 2.04% solution. If the ratio is 3:1, one pass of 1.6% should take you to 2.2%. Given the limited accuracy of sap hydrometers, (was it 1.6 or 1.8% to begin with?) I think the numbers seem to add up.

[Kev]

thanks for the updates!

[Old-Timer]

I think you will find if you put your membrane in series instead of paralell you will get much better results.

[jrgagne99]

I’ll try out running in series, but I don’t see how that could improve my water removal rate. I’ve found that the membranes provide the best permeate flowrate when using raw sap, not concentrate. Hooking them up in series will provide the first membrane with raw sap, but the second membrane will get concentrated sap to deal with- its performance should drop. In parallel, they are both filtering raw sap. In terms of pressure drops, in series, the pressure in the second membrane would be *slightly* less than the first membrane, or for two parallel membranes. So in that light, running in series would reduce performance even more. The only upshot that I see for running in series is that I would get more-concentrated sap, but the amount would be reduced. What I’m really after is the fastest water removal rate I can get.

[Gary in NH]

Running is series should remove almost the same amount of water and bump up your sugar content by what you would see in one additional pass through the system. If the increase in sugar content is a larger percentage than the reduction in flow it would make sense. Just swap the membrane positions every couple of hours to even out which one sees the higher concentrate. Whether you look at it like you are removing water or increasing sugar you get the same end result, less boiling. The filter cartridge has a radial flow with the inlet and outlet both at the the top of the housing. The flow at the bottom of the filter will not be anywhere near the flow going through the top, particularly at a low flow rate which is why they don't rinse out. It doesn't take much stagnant accumulation on the filter to give an off taste and odor. Consider you can't see anything less than 70-microns in the sap with the naked-eye and then think of what's in the sap down to 1-micron. It is all collecting both internally and on the surface of the filter. I always taste the permeate and concentrate when I start up the RO to see if there is any off taste. The only time I have ever had a problem is when I left a pre-filter in the system after flushing.

[jrgagne99]

So if I rinse after every RO session, I should throw out the prefilters after every RO session? If I use the RO every day that will start to add up $ after 4-6 weeks of sugaring season. Do you know a good source for cheap but effective pre-filters? Do you think its necessary for me to go down to 1-micron, or might I be ok to use just a single 5-micron prefilter? I guess I'm just looking for ways to cut cost a little if I need to use a new filter every day. Maybe I could rinse/clean the filters with a garden hose, or maybe by boiling them?

So far my, syrup made from RO'd sap is very tasty. I've used the RO for about 40 hours with four RO-water rinses and no pre-filter swap-outs. I made 2.5 gallons from 4% solution last night and it tastes great. But then again, my RO hasn't seen temperaturs any warmer than 45F yet.

[Gary in NH]

I use only one filter, a 1-micron spun-polypropylene. I don't think it matters if you use 1-micron or 5-micron. Neither one clogs up and they are the same cost. You don't really need two filters. Rather than leave one housing empty remove the housing if you can. If you wanted to really rinse a filter well you could use the second housing with larger fittings and reverse the flow so the water goes backwards from the inside core to the outside at a higher flow rate - like a backwash. I wouldn't boil them or heat them without finding out the temperature rating as the fibers may distort and lose their ability to filter. As I mentioned I had a problem with an off-taste when I left one in the housing after a long rinse so I throw it away after every use. I'm usually running 70 to 150 gallons of sap through to 8 1/2 to 11% sugar so it's not a big cost compared to the fuel savings. I'd rather throw out a used filter than risk a batch of syrup.

[jrgagne99]

My season is coming to a close today, so this might be my last post on this thread. In summary, I am very pleased with the system and think that it makes pretty good sense for the small producer of 50-100 taps. I am consistently getting 3-4 gph permeate out of my two x 100 GPD residential tapwater RO unit. I can concentrate up to about 4%, and have reliably reduced a 50 gallon juice barrel to 30 gallons in a 6 hour period. This is a nice benefit for a producer with 50-100 taps on vacuum, and not bad for a $300 investment. It won’t turn 100 gallons of sap into 25 gallons in less than an hour like the big units but don’t forget that it’s only a fraction of the cost.

Improvements for next year:
1) Add two more membranes in series, but mounted in parallel to the first two.
2) Remove the 5-um prefilter. Its added weight and no real benefit. A single 1 um filter is fine.
3) Mount the system on a lighter, easy-to-clean, easy-to-transport frame. The plywood platens I used this year are heavy and not maintainable.
4) Figure out how to feed it sap from the bottom of my copper coil stove-pipe preheater during boiling times. I observed about a 30% increase in permeate flow for 50F sap vs 35F sap. 70F sap will be even better, and could significantly increase RO throughput during boiling.
5) Figure out a way to run it, or at least keeping it from freezing without bringing it inside during periods of freezing temperatures. I’m thinking that a small blueboard-insulated “RO box” (kind of like an RO room) might be all it takes, since the unit uses about 150 W when on. A 100W lightbulb inside should do the trick when it is off. Insulated lines to and from the sap and permeate tanks will *probably* be enough to prevent freezing in most conditions. The lines should be removable so they can be brought inside on the occasional extreme cold nights during the early part of the season.

[jrgagne99]

With my season over, I need to store my membranes for the off-season. I finished with a 4 hour permeate rinse, but I’m wondering if there is anything else I should do as far as cleaning, and what kind of solution, (if any) I should store them in. Also wondering where I can get the suggested chemicals and/or preservatives. Any recommendations out there?

[to100]

I am interested in doing what jtgagne99 did but for a smaller operation 10 -25 taps, maybe with 50 if I wanted to max out my back yard. Would this work for me and if I only had 1membrane and 1 filter?

[jrgagne99]

If you're only going to use one membrane, I'd go with the 150 GPD residential membrane from wateranywhere.com. I bet you would get about 2 gph of permeate when running cold sap at ~100 psi with the Aquatec 8800 pump. use just one 5 micron prefilter. 2 GPH of continuous "water removal" could be a significant help to your operation, especailly if you're only boiling on say, a 6 GPH half-pint evaporator (or less).

[500592]

How long do you think you could run this before cleaning the membranes and to clean them do you just run permeate in the opposite way or how do you clean them

[jrgagne99]

I ran it 24 hour once, with no apparent degradation in the quality of the syrup produced. I just rinsed with RO water for two hours after every use, and at the end of the season. No back flush or anything fancy.

[500592]

Thanks a lot

[Weekend Mapler]

Thanks to JR, Gary and Teuchar for all the information provided on this subject. Any updates on improvements made for 2012 and how the system is working out this year?

I just took the plunge and purchased most of the components and am hoping to test out a system similar to yours this weekend or next. I'm going to use the aquatec pump and hope that head pressure from my feed tank will help it push to 100+ psi, one 1 micron filter and three of the 100GPD Filmtec residential RO membranes. Wondering if I should run them in series or in parallel, or maybe the first 2 in parallel that flows concentrate into a third? I found the high pressure 1/4" polyethelene tubing at Grainger and will use that in the event I want to add a procon pump and upgrade to the Filmtec TW30 2.5x14 or 2.5x21 like Gary. I thought about starting out with that setup given Gary's good results, but between the pump, housings and membranes for that system, it got to be too expensive for an "experiment."

Lately I can only get to my sugarbush to boil on the weekends, so I'm hoping I can run the RO Friday night and while boiling on Saturday and Sunday to help speed up my overall boil time. Will post schematic, costs and pictures for everyone if I get it together and running.

[Weekend Mapler]

5547

5550

Posting parts list with price and sources and schematic. Can't get a higher quality version of the schematic uploaded for some reason.

[Kngowods]

Jrgagnee99.. How is this ro working are u still happy with it???

[jrgagne99]

The system is working out very well. This year I added two more 150 gpd membranes, so 4 total now. From 2% sap, I'm getting about 7 gph water removal (permeate) and 7 gph concetrate at about 4%. Next year, I'll probably add 2 more membranes for a bit more water removal. It makes a world of difference in my 150-tap operation. I built a small, insulated RO cabinet for my unit and put a 40-watt lightbulb inside. The light bulb is on a temperature switch that keeps the temp between 35F-50F. I can select whether to process cold sap from the bulk tank or during a boil, warm sap (~80F) from the bottom of my copper coil that's wrapped around the smoke stack. The warm sap flows a bit better, up to 8-9 gph permeate flow. When I do this, I switch the concentrate so it goes directly into my steam-away (also homemade :) ), to avoid microbe growth issues, etc. I'll try to post some pictures of my setup in the next day or two. I use a 1-hour permeate rinse at the end of each night, and change the 5-micron prefilter every couple days. Finished the season with a 3-hour permeate rinse. Then I replaced the 5-micron filter with the AMH membrane preservative cartrdige from wateranywhere.com. This supposedly makes just the right solution of preservative. I ran it through for a few minutes to make sure the solution was in all the membrane housings, then shut it down, and put the whole thing in my nice cool, dark basement- piece of cake.

[rchase]

Has anyone built a ro using bigger membranes like 4x40 or 8x40 membranes? im looking for something that will do 100gph.

[Kngowods]

Jr that sounds good I think well be making one very similar to yours for next year!! You said you had less than $400 in it

[NH Maplemaker]

rchase,there has been several menbers on here that have done just that with some very inpressive results! Member 3% solution made one for this past season and was removeing 65% of water taking 2%up to 6% in a single pass! He is a friend of mine and I know he would love to share his results and plans with others. Find he contact info on the member list than E-mail or PM him.
MFarmal also built one with about same results!! JimL.

[jrgagne99]

Here are a few photos of my setup, including the RO.

[moeh1]

If you were starting over, would you go with this or get one of their low energy 2-1/2 by 21 membranes, a housing and a suitable procon pump for 150psi? At first glance it seems like that might give even better performance at similar cost, but I still have a lot to learn about RO....
Marty

[jrgagne99]

Moeh1- You make a good point. When I started this I was at 110 taps and I thought I was done adding taps. Now I'm up to 140, and probably going to add 20-30 more next year. So its getting to be a bit undersized...

But if i were to do non-residential-tapwater membranes, I would skip the 21" membranes and go straight to 40" long. Member 3% solution, with his homemade RO, is processing sap at 35 gph with 50% water removal on a single 2.5"x40" XLE. I think I could build this for about $500, using PVC housings (not SS) and a cheap used motor and procon pump.

When I add my last two membranes next year, I'll maybe get 25-30 gph with 50% water removal. I like the compactness of my unit, but for more than 150 taps (I'm probably headed in that direction, after the disappointing year this spring) I'd go with a 2.5x40 or 4x40. No re-circ or feed pump, and straight manual operation is the way to do it on the cheap.

[moeh1]

That feedback really helps. I'll be where you are in a couple years and I'm torn as to how to approach a low bucks homemade RO. I can get ~140-150 trees on my property total, but have a couple neighbors with a few trees that like syrup. Still studying approaches. I liked your machine, but thought I'd outgrow it. As your thread evolved,I really knew it. I need more info on 3%'s machine!
Marty

[NH Maplemaker]

Marty, just send Dave(3%) a PM ! We are good friends so I know he will tell you anything you need to know about his home made RO! JimL.

[moeh1]

Well, I already had a line on 2 tw30 membranes 2.5 by 21 quite reasonable. That just came thru, so I guess I will be basing my design around those. I think I'm better off running them in parallel, but still learning.
Marty

[TunbridgeDave]

I saw a few posts about where to get cheap filters and this is where I get mine. http://www.filtersfast.com/Pentek-PS5-10C-Sediment-Filter.asp

[jrgagne99]

Moeh,
I think you're better off to run them in series. In series, the flow through each is about the same (less the water removed by the first membrane). In parallel, you split the flow in half between the two membranes. As I understand it, higher flows over the membranes are preferred to prevent bacteria buildup, especially if you don't have a recirculation pump. I once had it explained to me as: A fast-running brook is much less apt to grow bacteria and algae than a slow meandering stream.

[moeh1]

I'm studying this issue, been reading some industrial design manuals. If the first membrane doubles the concentration, the second membrane only sees 1/2 the flow anyway. I "think" the fastest water removal is parallel, as long as you aren't looking to get high concentration levels. So, the current conclusion is if the pump allows for good flows rates, you can get good flow and water removal? Love to hear from some folks with more experience.
Marty

[Snowy Pass Maple]

I would take the advice above and go in series. You won't double the concentration in the first membrane unless you are recirculating within that membrane or running it way too slow. All of these low cost homemade systems are single pump, which are best suited to recirculate using something like a 55 gal drum. But you can run like this and easily hit 5% sugar - which is just awesome for a backyard guy used to boiling straight sap! Even more so if you get into Birch!

If you look at the membrane data sheets, you often need to flow across the membrane at a minimum of 5X the rate you remove permeate for tap water. For stuff that has biological concerns, you should be thinking about going up closer towards the maximum flowrate spec. It'll take a more expensive and power hungry pump to maintain these flows across two parallel membranes vs. one line with the membranes in series.

Some other feedback I'd offer is that I tried both an array of residential housings and a single 2.5" x 21" housing using a nanofilter. I found that the 2.5" format held up much better against fouling and showed flawless recovery to maximum flowrate with NaOH + Na-DSS washes - I did not find this to be true with the residential membrane housings. This was particularly pronounced when using it on birch sap which seems to be a more challenging case than maple sap - I suspect this could be due to higher TDS in birch sap as it precipitates like crazy as you boil it. The commercial housing will generally cost you more, particularly based on retail web pricing, but I think it's worth it given that it performed so well in both of these applications.

If you then contemplate 21" vs. 40" - it depends on how many taps you need to run and what size pump you're going to use. A single 40" membrane/housing is more economical than two 21" membranes/housings. (roughly 60% more cost effective after normalizing cost/performance)

So why would anyone want a 21"? I have based my design around a prototype low voltage pump that can support a 21" membrane with ease, but would have a more marginal flowrate for a 40" membrane. Aside from using very little power (<100 watts) this design can be run off deep cycle batteries for extended periods. That could be an interesting option for people without power in their sugarbush that may still want to use a RO. It's far quieter and more cost effective than running a gas generator as well. Since I was also able to do this for much much less cost than a procon pump/motor, these considerations tipped the scale for me. In fact, despite the economy of scale on the membrane side going from (2) 21" housings to (1) 40" housing, I think I could still build my system cheaper using two of these pumps in parallel on parallel 21" housings to nearly equal the 40" performance. This would also provide the ability to run one while one cleans, have redundancy in case either side is down, start smaller and expand upward, etc.

It also depends on the size of your operation. I have been working on refining a design that could work for smaller hobbyists that want to expand and are interested in a RO using commercial grade components all assembled on a frame for under $1000 in lieu of bigger evaporators. A 40" membrane / high volume procon pump makes that goal much harder to hit; a 21" membrane / low voltage pump could let someone get started with RO for a lot less money, still provide a relatively cost effective and modular way to double capacity - beyond which point someone may finally be ready to step up to one of the Ray Gingrich ROs. Many people will never get close to that level - or want to spend $2500+. I have been so pleased with RO that I can't imagine not using one - I was just not ready to spend thousands of dollars.

Of course if you have a cheap high volume pump and ample power already available, then certainly go with the bigger membrane - you'll just be done faster!

[moeh1]

OK the series comments are starting to make more sense. The stuff I've been reading is all based on trying to keep the clean water, so I need to think from the other perspective....I don't mind the idea of a re-circ pump if it will speed things up and allow the membranes to stay cleaner longer. From what I saw on th procon site, their pump is limited to 250 psi, while the membranes and housings are good for 300. What is a good pump setup option to consider?
Marty

[AustinHills]

I started small last year and loved the process (and results), but the wife isn't so keen on the long boil times taking me away from the family. As a result I'm looking at RO as a potential solution (also working some arch improvements). I think this system could work well for me given the relatively low cost for performance as well as the potential to use the permeate for my other new hobby of wine making.

I have a question that I was not able to find a clear answer to in the forums. What capillary tube / flow restrictor size should be paired with the membrane? The manufacturers recommend the tube with the same rating as the membrane. This is something I haven't seen on anyone's shopping list tho.

Early in this thread Jrgagnee99 mentioned using a 50gpd tube with 100gpd membranes. There was also some talk of using needle valves to provide the proper back pressure.

What are folks doing most successfully?

Since I'm only looking at ~40 taps (last year was obviously a tough year to start, so now I have no idea how many taps I can actually handle if we have a decent year...) I think 3 or 4, 150gpd membranes would be plenty.

[hodorskib]

I put together a system last year and it worked great. I was getting consistently 8% concentrate. I did not use the cap. flow reducer but rather installed a needle valve at the end of the concentrate line. Send me a PM with year email and I will send you a detailed schematic drawing of my setup.

[jrgagne99]

Autsin Hills,

The smaller orifice size will create a higher back-pressure on the membranes. So you actually want to use the smallest flow-rate restrictor valve that they sell (10 GPD on wateranywhere.com). If you use the 150 gpd membranes, make sure to get the membrane housing with the inlet port on top, not out the side. These ones are cheaper anyway. The 150 gpd membrane doesn't fit in the housing with the inlet port out the side.

[2kviper]

Does anyone have a set of plans on how to build one of these small ro machines and where the parts are available?

[jrgagne99]

See posts #1, 5, and 39 on this thread.

[wildlifewarrior]

Hi jrgagne99
Did you end up changing your membranes? I plan on building one of these next year for about 150 taps like you mentioned this year. How did it stand up this year? any new suggestions?

Mike

[jrgagne99]

Still using the same membranes. As it stands right now, my setup has two 100 gpd membranes (two years old) and four 150 gpd membranes (two are 1 year old and 2 were new this year). I haven't benchmarked each membrane in a while, but I suspect that the flow over the last membrane is pretty low, and the concentration (6%) may be approaching the membrane's limit.

The setup processes about 15 gallons of raw sap per hour, converting to about 6% in one pass (10 gallons to permeate, 5 gallons to concentrate). I usually process the day's sap overnight, then boil the concentrate the following evening. It's not ideal for the concentrate to sit for 12-18 hours, but it is what it is. Sometimes I'll process yesterday's sap during the day while I'm at work, then boil the concentrate when I get home. My evaporator boils at about 15 gph, so I would need 3x more RO throughput to be able to feed the evaporator it in real time.

I love my setup since it cuts my boil time by 2/3. But if I had to do it again, for 150 taps, I would consider using two 2.5"x 21" membranes, or maybe even two 2.5"x40", so that I could feed my evap in real time. This issue there is flow rates. I think the Aquatech pump is a bit too small to provide the required flow over the membranes, so a recirculating pump would probably be needed. Maybe even two aquatecs to get enough flow. With small membranes like mine, you need to run the RO long before you start boiling, and consequently, the concentrate ends up sitting for a while. I haven't experienced spoilage yet, but I suspect that my grade may be suffering somewhat as a result. Could be a bigger factor during the warmer end-of-the-season.

[wildlifewarrior]

Now when you guys mention 21'' or 40'' I am assuming thats the length, but looking at your original posting specs, and searching the internet I cannot find any matches which were 21 or 40''. Do you know, or does anyone else know what the parts numbers on these are?

When you guys mention a recirculation pump, does this just add additional pressure to the system? Or does it actually mean recirculation like, pumping it back into the stock tank from another tank?

Is it possible to attach two pumps together to increase flow?

Thanks guys
Mike

[saekeaton64]

Yes, 21" and 40" refer to the length of the membranes, they also come in different diameters ( 2, 2.5, 4, and 8").
www.wateranywhere.com has a really good list of different sized membranes at decent prices.
The recirculating pump is a second pump that is added into the system, it takes a percentage of the concentrated sap that has already went through the membrane and re-injects it into the feed line going to the membrane. By doing this the total flow rate over the membrane is increased which keep the membrane from getting plugged up.
The question about attaching two pumps together to increase flow - it depends on the pumps being used, and the max inlet flow and pressure; if you are hooking the pumps up in series the second pump may be damaged if you exceed the max specs. Hooking the pumps in parallel would be the safest way to increase flow, this would be done by connecting both outlets together in a tee.

[bowhunter]

I planning to build an RO next year and have been gleaning some really good information from everyone on the forum. How are your membranes arranged? Are they all in series or do you have some in parallel? I took the Dow data sheets for these membranes and the Aquated pump curve and developed a spreadsheet to model the performance. It seemed to fit pretty well with the data from hdorskib. I believe he has three 150 gpd membrane in series. I would gladly post the output from my model so you can see how close it fits to your data. In the model I also used the Dow temperature curves to account for the lower flow with colder temperatures. In addition to the arrangement of the membranes I also need the pressure you're operating them at. I assume you're using the big Aquatech pump. I believe it does about 500 gpd @ 90 psi. I will assume the sap temperature is 36 degrees F.

Thanks,

Dave

[wildlifewarrior]

Hi everyone some more questions from me,
Most of the filters i found at wateranywhere are 11'' for 100gpd residential. What woul the difference be between the different lengths if they process the same amount?

If i plan on processing 150-200 gpd would i need membranes rated 150 or 200 run... in series? Would running several 100gpd in parallel be able to process a highr number of gpd than ther are rated since they are in parallel as long as your pump is strong enough?

Thanks
Mike

[bowhunter]

Mike,
The rating on the membrane is the gallons of water it will remove. The flow through the membrane should be about 5 times the membrane rating so a 100 GPD should be fed 500 GPD of sap. Do you know the % sugar or Brix of your sap? The biggest Aquatech pump will only deliver about 500 gpd at 90psi so it will only supply enough flow for one or two 100 GPD membranes in series without using a recirculation pump. Two 100 GPD membranes in series at 100 psi should be able to take 200 gallons of sap up from 1.5 % to 6.5% sugar in 16-18 hours. That assumes that you recirculate back to the sap tank that you're pulling from. I used 36 degrees for the sap temperature. If the temperature is higher it won't take as long. If the flow is too low the membranes will foul and the performance will drop off substantially. A lot of people on the forum do operate with lower than design flow through the membranes and get good performance, but I know several have had issues with fouling at the lower rates.

[wildlifewarrior]

Bowhunter that makes so much more sense now!! I really appreciate it, that was probably the key bit of my understanding which i needed to get my brain around before going forward with this.

Our sap is between 1.5 and 2%, we got mostly reds. So 2 100gpd membranes should be plenty?

I really do appreciate all you help.

Mike

[bowhunter]

As long as they don't foul too much, two 100 GPD in series should be enough. This isn't an exact science so your experience might be a little different, but in any case you'll have a lot less sap to boil than you do today. Make sure you put a 5 micron sediment filter ahead of the membranes. You should only need one filter housing, but should probably have several spare filter elements so you can replace them as needed so you maximize the pressure to the membrane. You also need to flush the membranes with several gallons of permeate, which is the reject water, after each use.

[not_for_sale]

I am not sure why you would go with a 100 GPD when the 150 GPD doesn't cost much more. Running them in series is not a good idea. The second one will foul in no time flat. My Aquatec 8852 will handle three 150 GPD in parallel with cold sap. With warm permeate that is another question, but sap is not a problem. One 150 GPD will remove 2 GPH of water from raw sap. That is the top performance. It goes down with the sap Brix increasing.

The difference between 100 and 150 GPD is the area of membrane. The 150 GPD is 50 % bigger.

[bowhunter]

Use a 100 because it matches the pump capacity. If the pump was bigger you would use a higher flow membrane. Your second membrane probably fouls because the Aquatec 8852 doesn't produce enough volume for adequate flow to the second membrane if you're squeezing the first 150 hard. Also if you're watching the flow from the second membrane you may be seeing the impact of the osmotic pressure increasing across the first membrane. For example a membrane will only flow about 28% as much permeate at 6% sugar vs. 1.5% sugar.

Each 150 should be fed 750 GPD. If you're using a high capacity recirculation pump that will pump 2250 GPD then you should be fine with three in parallel. Bottom line you can get a lot of combinations to work, but if you design to fit the equipment you have, the system will perform more reliably. You obviously can use 150's you just don't enough pump flow to satisfy the design flow through the membrane and the membranes foul more quickly. That's right off the Dow data sheets.

[not_for_sale]

Theory is good, experiments are better :-))

My experiments show that second and third membrane are not adding anything to the picture if the system is running for longer than 2 hours unattended. With 3 in parallel I ran 10 hours and the system performed the same on raw sap. With the membranes in series I needed to do a wash, flip the membranes etc. in order to go to back to original performance.

Parallel is better than series.

Also, theoretical flow and practical flow are different. As I said, one membrane removes 2 GPH in water, 3 membranes 6 GPH. If in parallel.

So feed flow needs to be 30 GPH to stay at almost maximum spec. That is 0.5 GPM or 1.9 LPM.

If Brix are higher, flow is lower.

Very close to what one aquatec 8852 does. Especially on hire Brix sap.

So, theory is good, practical experience is better.

[Clinkis]

Just curious if anyone has found affordable low flow meters that work well with this application. I am also experimenting with a homemade RO and would like a better way of measuring my flow rates other then a measuring cup and a stop watch! I have found some online but most are too expensive.

Also wanted to chime in with my 2 cents on series vs parallel. I run my membranes in series and experience no loss of flow rate or concentrate level for up to 14 hours. Currently running 3.2% up to 6.7% at about 5 gph.

[not_for_sale]

My concentrate that I started boiling with this morning was 10.9 percent.

[not_for_sale]

There is a seller on eBay with a 20 dollar flow meter. I also find a digital one for 20 bucks. I gotta look somewhere thou to find the exact address.

I am very fast at 7 percent. Less than 2 hours on a 55 gallon barrel. But I also run the membranes at 120 psi regularly.

[Clinkis]

Has anyone used these on a homemade RO?

[bowhunter]

If you want to see some information from the experts on RO, look at this presentation by http://maple.h2oinnovation.com/wp-co...g_2011_ENG.pdf posted by Bill Mason. It's very clear from the presentation that the key to good performance is not exceeding the maximum permeate recovery rates. You can run in parallel or series as long as you size the system properly and run the membranes with the proper recovery rates.

The Aquatech will pump less than 500 GPD if the pressure is over 100 psi. The 150 GPD membranes do have more surface area than the 100, but it is more difficult to keep them from fouling longer term without enough flow. They are designed for 750 GPD of feed with 150 GPD of permeate. You would have to drop the pressure on the system to 30 psi for the Aquatech to pump enough to meet the flow requirements for one 150 GPD membrane. At 30 psi you will get almost no permeate flow. I'm not saying running three 150 GPD on this Aquatech pump won't work, but you're way outside the range the membranes were designed to operate and that's probably never a good idea.

Guys I'm just trying to share my 40+ years of engineering experience using the data that many of you have provided along with the manufacturers data sheets to provide some guidance so that everyone doesn't have to do trial and error on a small scale. Even a small system will cost $300 to build. If you build it wrong or don't operate it correctly, it won't work well or won't be reliable. For whatever it's worth, I have a BS in Chemical Engineering and was registered to practice in two states. I worked in the chemical and oil processing industry for 40 years and have been in responsible charge of hundreds of $millions of chemical plant designs and operations worldwide. None of this makes me an RO expert, but I probably can offer some sound technical advice.

[not_for_sale]

Bow hunter, you link isn't working.

[not_for_sale]

You will never get the rated permeate flow out of a membrane with cold sap running it at 50 psi (the spec). The aquatec 8852 won't provide 100 psi without feed pressure. And, it is designed for 150 GPD membrane flow with feed pressure. The 68xx and the 8851 aren't. If you provide feed pressure the Aquatec 8852 runs perfectly at 850 ml a minute of concentrate. If you increase that flow it won't.

So, either way, you are running outside of spec. Scrap the project or not?

As far as I am concerned, at 84 bucks (3 membranes) for the season I am removing 80% of the water. Fuel savings alone will cover this. Not to mention time to boil.

So, what if I have to scrap the membranes at the end of the season? I doubt it though! They are recovering perfectly right now. And all I have done is a permeate wash with 40 centigrade permeate followed by cool permeate with H2O2. No RO soap yet.

[wiam]

http://maple.h2oinnovation.com/wp-content/uploads/2011/04/H2O_Innovation_Maple_Membrane_Training_2011_ENG.pd f

[Meltbrass]

I built one and used it this season. 4 ea 150 gpd membranes in series.

Thank you for the extra sleep and reduced wood required.

[bowhunter]

It sounds like your system is working ok for now and if you're able to get through the season without replacing the membranes then you're ahead. Not sure why the link didn't work..sorry about that. I understand the the permeate flow is affected significantly by the temperature. Unfortunately most of the residential membrane manufacturers don't give you any factors to adjust for temperature. The ones I've seen are for the Dow filmtec's. With the Dow 100 GPD you lose about 50% of the permeate flow at 40 degree F. If you want or need to run three 150's in parallel then it might be a good idea to buy a pump like one of the Procon models (125 GPH) with enough capacity for all three, but I would wait to see if your membranes survive more than one season. If they don't then the pump expense might be justified. It might be that with routine peroxide washes you keep the membranes clean enough so that you can ignore the minimum flow requirements.

[not_for_sale]

My residential system has seen over 500 Gallons in the past week, and still running strong. Not too bad for $300 in parts.



Pretty good price for these components on Amazon. Amazon has been one of my favorite supplier for this stuff.



Pumps:



1. http://www.amazon.com/gp/product/B0099TTV76?ie=UTF8&camp=1789&creativeASIN=B0099TTV76&linkCode=xm2&tag=mapletrader-20



2. http://www.amazon.com/gp/product/B000LDG4L0?ie=UTF8&camp=1789&creativeASIN=B000LDG4L0&linkCode=xm2&tag=mapletrader-20



3. If you get the Aquatec, make sure you get the 8852 - some sellers sell an 8800 pump and then its likely the low flow pump. My Aquatec can handle three 150 GPD membranes in parallel with cold sap easily. This Amazon price on it is only $79 right now - pretty inexpensive: http://www.amazon.com/gp/product/B00A7ZV2GO?ie=UTF8&camp=1789&creativeASIN=B00A7ZV2GO&linkCode=xm2&tag=mapletrader-20

You can get two of these Aquatec and run them in series for double the pressure or run them parallel to get more flow so that you don't have to wash so often.



Membranes:



1. http://www.amazon.com/gp/product/B000WPHUAG?ie=UTF8&camp=1789&creativeASIN=B000WPHUAG&linkCode=xm2&tag=mapletrader-20



2. http://www.amazon.com/gp/product/B004BG5ETG?ie=UTF8&camp=1789&creativeASIN=B004BG5ETG&linkCode=xm2&tag=mapletrader-20



The stainless housing for the XLE 4040 is actually cheapest on ebay. There is a seller selling them for $80. Amazon sometimes has the housings for the residential membranes at $7.00 plus shipping.

I haven't used the XLE membrane yet. I got it just because if the system wouldn't hold up I'd have one. So far so good. I actually have back washed with RO soap. See my next post.

[not_for_sale]

Here is what I use to backwash. RO soap is actually lye (NaOH). This is pure lye (food grade even though it says drain opener :) ).



http://www.amazon.com/gp/product/B002BW4MV8?ie=UTF8&camp=1789&creativeASIN=B002BW4MV8&linkCode=xm2&tag=mapletrader-20



In order to backwash with this - you need to make sure you know the PH of your back wash water. You can either get a PH meter, or, your could just get PH strips. Effective backwash is at a PH of 12. Some recommend a PH of 11. 12 is more effective though.



The review on the meter are kinda bad, so I just used strips. Also, you need calibration solutions for the meter. In all, for this season I am using strips.



Strips: http://www.amazon.com/gp/product/B001T77WW2?ie=UTF8&camp=1789&creativeASIN=B001T77WW2&linkCode=xm2&tag=mapletrader-20



Meter: http://www.amazon.com/gp/product/B004G8PWAU?ie=UTF8&camp=1789&creativeASIN=B004G8PWAU&linkCode=xm2&tag=mapletrader-20

[bowhunter]

Stick with the strips. The meters are too dicey.

[jrgagne99]

Not_for_sale: What are you doing for a backwash? You don't actually mean flowing in reverse somehow, do you? I've only ever done liberal rinsing after each run. My runs are generally about 12 hours long. Then I follow up with a 4 hour rinse. During rinse, I generally back off the restrictor valve to get more "concentrate" flow, changing from a 2:1 (perm to conc) during sap processing, to a 1:1 during rinsing.

[not_for_sale]

Back wash is just a term. I wash with permeate as you do, with the filter in. I send about a gallon of permeate through and collect the sweet. I then back off on the pressure and run 5 gallons through and chuck the concentrate. I then use 2 gallons of permeate cold, and bring 2 gallons to a boil, and mix it all with a quart of peroxide. I then recirculate that mixture for a while. Chuck it again, and then cool down with cold permeate again.

I don't observe any specific time on the cool down however, I've done that every morning while I collect new sap. I collect in the morning because I want the ice in my barrels to keep them cold.


When I took the membranes out I saw that they do have a built up on them. That is when I took the filter out, and ran a 12 PH solution of lye at 115 F and rinsed for about a half hour with permeate. Checked the membranes again and they were squeaky clean.

I now have put my UV in front of the filter before it all goes into the pressure pump. No more built up of slime anywhere.

I am planing a wash with lye again this morning.

[Starting Small]

But if i were to do non-residential-tapwater membranes, I would skip the 21" membranes and go straight to 40" long. Member 3% solution, with his homemade RO, is processing sap at 35 gph with 50% water removal on a single 2.5"x40" XLE. I think I could build this for about $500, using PVC housings (not SS) and a cheap used motor and procon pump.

When I add my last two membranes next year, I'll maybe get 25-30 gph with 50% water removal. I like the compactness of my unit, but for more than 150 taps (I'm probably headed in that direction, after the disappointing year this spring) I'd go with a 2.5x40 or 4x40. No re-circ or feed pump, and straight manual operation is the way to do it on the cheap.
Jrgagne-Just wondering if you ever ended up building the 35 GPH RO for $500 that you had mentioned? Anyone try doing one this size? Sounds like from other threads the 100gph is going to cost somehere around $1000 to build yourself. Thanks,
-Dave

[jrgagne99]

No, that was never my plan.

My rig is topped out with six 150 gpd membranes. If I remember correctly back to last spring, I get about 60% water removal. It processes raw, cold sap at about 15 gallons per hour (converting to 10 gallons water, 5 gallons concentrate). I run at 120 psi, with the membranes in series.

[Greenthumb]

So after just finding this thread for those who have done this. I was wondering if you could answer some questions for a guy who was looking at upgrading to a smokey lake full pint on my leader half pint is it worth trying this first. Building my own small ro setup. We tap anywhere from 50-75 taps usually. Boiling is fun for the first hour. By march I hate wood, sap, pancakes, syrup, anyone who tells me what a neat hobby you have. By June I'm thinking how I miss syrup season. Could this maybe help me be a little less bitter for a third of the cost of upgrading pans.

Thanks

[Flat Lander Sugaring]

So after just finding this thread for those who have done this. I was wondering if you could answer some questions for a guy who was looking at upgrading to a smokey lake full pint on my leader half pint is it worth trying this first. Building my own small ro setup. We tap anywhere from 50-75 taps usually. Boiling is fun for the first hour. By march I hate wood, sap, pancakes, syrup, anyone who tells me what a neat hobby you have. By June I'm thinking how I miss syrup season. Could this maybe help me be a little less bitter for a third of the cost of upgrading pans.

Thanks
you build a single membrane unit it would be plenty for that. I would do that before upgrading your rig. I had 1400 into a two membrane unit so half that probably less, I bought expensive membranes. Save about 250 by going to XLE.
after your boil with concentrate you will never want to go back to raw sap

[bowhunter]

If you only have 50-75 taps then you can probably build small unit based on home RO membrane for less than $500 using new components. That's probably half the cost of the smoke lake pan. Here's the link to a design posted on this forum. http://mapletrader.com/community/showthread.php?18888-Flux-Capacitor-(-Home-Made-RO)&p=212073#post212073

[Greenthumb]

Flat lander - question what do you mean by save 250 by going to XLE.

[Flat Lander Sugaring]

Flat lander - question what do you mean by save 250 by going to XLE.
I paid around 325 a piece for membranes, i think i found XLE membranes for 225 a piece, so 200 to 250 savings

[Greenthumb]

Let the madness begin. My pump arrived yesterday and the membranes and housing will be here early next week. Hoping to get all tubing from the the local lowes. Trying to fashion a system to help out our half pint.


Sent from my iPad using Tapatalk

[stoweski]

Curious Greenthumb, what make/ model of pump & membrane did you end up getting?
Putting together my own RO as well. Picked up an XLE-4040 and will be getting a Fluid-o-tech pump soon. Headed to Lowes in a few minutes to pick up some electrical stuff and some PEX to get me started.

[Greenthumb]

I am going to fashion the unit after what I saw on here from a member using 3 or 4 100 gallon per day membranes. I bought a 8852 aquatec pump and three 100 gallons per day membranes and housings. here is the link to his website I'm trying to duplicate. We only tap 75 taps so the hope this could really speed,up boiling on the half pint and since most of our trees are reds so our sugar is usually around 1.8 after the first run. Here's the members site I'm using as a reference

https://sites.google.com/site/mattatuckmadnessmaplesyrup/home/homemade-reverse-osmosis-system

[Machinist67]

I built this unit last year and it removes 70% of the water and I only have to boil 18 gal to 1 gal. Buy the automatic float and let it run over night if it is not too cold.

[Greenthumb]

Membranes and housing arrived today. Going to be getting plumbing tubes and fittings later this week hope to have housing idea also. As I looked over the membranes just want to double check the permeate comes out the center of the mebrane and the concentrate sap will be what does not flow through the membrane correct. Thàt is what I want to collect for boiling

[Flat Lander Sugaring]

Membranes and housing arrived today. Going to be getting plumbing tubes and fittings later this week hope to have housing idea also. As I looked over the membranes just want to double check the permeate comes out the center of the mebrane and the concentrate sap will be what does not flow through the membrane correct. Thàt is what I want to collect for boiling
Correct you have holes in center of end caps and ones off center. Input side of caps the center gets plugged output side is your permeate.

[Greenthumb]

Ok last novice learning on the fly question than. The membrane housing has two ports at the bottom. One port is channeled to the center of the membrane the other port is channeled to the out side which port will dump the concentrate (what will boil) and which port will be the permeate (hopefully pure water removed). The port on the right is channeled to the membrane port in the center of it. The port on the left on the outside of the membrane if that makes any sense- Pic included8550

[jrgagne99]

If memory serves, the center port is the permeate. One way to find out... make some 2% sugar-water solution and see which one is sweet and which one is water! You'll be doing all kinds of experimentation as you build and use this thing, so you might as well get used to it!

[Flat Lander Sugaring]

here pic of mine, I bought 3/4 port end caps for supply side I kept 1/2 ports for discharge
85698570857185728573

[Flat Lander Sugaring]

Ok last novice learning on the fly question than. The membrane housing has two ports at the bottom. One port is channeled to the center of the membrane the other port is channeled to the out side which port will dump the concentrate (what will boil) and which port will be the permeate (hopefully pure water removed). The port on the right is channeled to the membrane port in the center of it. The port on the left on the outside of the membrane if that makes any sense- Pic included8550
im going to say center is perm, one off center is concentrate, thats how a large membrane is set up at least mine

[stoweski]

Hey Flat, why did you count a tee to the pump? Or should I ask, what is on the other end of the tee that's connected to the pump? Is it a relief valve of some kind?

Also, what hoses are you planning on using to go from your feed pump to filter to main pump as it's not under a lot of pressure?

Thanks!

[jimmol]

I am moving my post to were it can be seen a bit better. Noticed I could not find it on the list unless I clicked the "more replies below..." link. Don't mean to jump or break any rules, just would like it to be seen so I can get more input.
Thanks to not_for_sale for addressing one of my question.

[not_for_sale]

I tried both, restrictors and a needle valve. I like the needle valve. I have the 8852. If you need to go beyond the 80 psi it gives you you need a feed pump. You can add the psi. However, make sure your feed pump is rated to run all the time. Most of these small pumps are either not food grade or aren't rated for continuous use. What you are looking for in general with small membranes is a way to remove 70- 80 percent of he water. I have 4 barrels that I reduce to one in two steps. I flush In between. The higher the pressure the higher he concentration, but the faster flow needed to not clog the membranes. One 8852 is not going to cut it when it comes to the flow. I would go parallel. That way your membranes fouls at the same rates.

[jimmol]

Going to try my hand at a homemade RO economy model as seen on https://sites.google.com/site/mattatuckmadnessmaplesyrup/home/homemade-reverse-osmosis-system. I am planning 3 membranes in series.

After reading this post I have several questions.

Regarding membrane recovery rate as viewed in the link http://maple.h2oinnovation.com/wp-co...g_2011_ENG.pdf; using the Aquatech 8852 rated at 125 psi - 80psi with 0psi feed, what am I looking for to have a correct recovery rate? The correct ratio for my 100GPD membranes? Or maintaining a certain pressure? or both?

To maintain the ratio, the author of the link uses a needle valve, but there has been mention of restrictors. Since, according to http://www.purewaterproducts.com/articles/flow-restrictors, restrictors give you predetermined ratios, would it be better to use restrictors instead of a needle valve? Would you use the same restrictor for all three membranes or change each one since the brix is increased?

Someone earlier in the post mentioned the aquatech 8852 won't provide 100 psi without feed pressure - I'm curious, if I need over 100 psi, how would I provide feed pressure? A second pump?

All this theory of RO is new to me so I apologize if I am asking something that was covered earlier, but I am just not up to speed to catch it.

Thanks

[jimmol]

Thanks for the reply. I have the valve on order and will see how that works.

I see what you are saying about the benefit of running parallel in regards to foul rate of membranes. Others have shared some positive points about serial installation. In looking for info on RO membranes I came across this diagram at http://puretecwater.com/what-is-reverse-osmosis.html. It shows going parallel into two, then series into one more membrane. Something I could try since I have 3 housing. Whether or not it is better than other systems or not remains to be seen.
8853


I guess the debate comes from lack of controlled testing of different designs. Whatever design we use is reducing water and that is the end result sought. If we are happy with what we have, that's fine. A few of us are more curious in nature...

I sincerely thank all of you for sharing your insight into RO systems and their pros and cons. There is so much information that sometimes my head swims.

[Greenthumb]

Since it's -2 right now and the 10 day forecast doesn't go above 30 I think I have time. Here are the parts for my homemade ro. Found a old computer tower I'm going to try to use for a housing. Going high tech with this system 89238924892589268923892489258926

[Greenthumb]

Fabrication department made some frame changes. Went with wood. It's 20 degrees for the foreseeable future. Should I test it with just plain tap water. Sap will be a problem for a few weeks. I still have a few fittings to go. Sorry about pics not sure895189508950895289538954

[Machinist67]

Run water thru it to flush the brine that the factory has in the membranes. You could then run some sugar water 2% and see how it works. Mine removed 75% of the water.

[hodorskib]

I agree mix up a batch of sugar water and give it a test. Two things to keep in mind:
1. The pump is only designed to push not to draw so make sure your feed tank is higher than you pump - gravity will solve this issue
2. Temperature plays a big roll try and use it in a heated space - I keep mine in the garage which stays around 50 degrees
If you could post some pics of the finished unit I am interested in how you mounted everything.

[Greenthumb]

8969897089718971. Can get pics right side up

[hodorskib]

Nice job it is always easier to keep everything organized when tinkering with this sort of stuff and by mounting everything it really helps.

[SDdave]

You could then run some sugar water 2% and see how it works. Mine removed 75% of the water.

Couple of questions on the Aquatech 8800 RO system.
1.) What is the optimal psi should it be running at?
2.) Does it matter if the sap is higher than 2%?
3.) Hydrogen peroxide rinse after each run or permeate?

I ran my system yesterday at 125 psi with 2.8% sap, right away I was getting a 3:1 ratio and sap was at 7.8 to 8%. Checked it an hour later and sap was at 6.3%. The permeate was constantly reading 0% at all times. At the end of the day I removed 66.6% of water, I was expecting 75%. I am extremely happy with the results (and so is the wife) I was just wondering if this is normal or should I be getting a higher brix.

SDdave

[Clinkis]

Couple of questions on the Aquatech 8800 RO system.
1.) What is the optimal psi should it be running at?
2.) Does it matter if the sap is higher than 2%?
3.) Hydrogen peroxide rinse after each run or permeate?

I ran my system yesterday at 125 psi with 2.8% sap, right away I was getting a 3:1 ratio and sap was at 7.8 to 8%. Checked it an hour later and sap was at 6.3%. The permeate was constantly reading 0% at all times. At the end of the day I removed 66.6% of water, I was expecting 75%. I am extremely happy with the results (and so is the wife) I was just wondering if this is normal or should I be getting a higher brix.

SDdave

I have the same RO. I found optimal pressure is around 125%, which you have. You are having the exact same problem I had when I first built my system. The guy that helped me build mine had 1.5%-2% sap and he told me same thing that he was removing 75% water. My sap is usually around 3% and I couldn't maintain the 75% mark either. I've learned a lot since then. For starters...the difference between 2% and 3% sap is huge (approx 14 extra gallons of sap required to get the same gallon of syrup). The higher the suger content of sap the harder it is for an RO to remove the water. Large commercial RO's use higher pressures to overcome this but this is not an option with our system without damaging the membranes or pump. Thus, with our RO's you need to slow the flow rate down to give more time for water to permeate out. This slows is down greatly but the bigger problem is this causes the membranes to foul and plug much quicker.

So this is what I found. If you are dealing with Sap in the 3% range a realistic target is 50%-60% water removal. This type of RO can maintain that for reasonable amount of time without requiring flushing or washing. Any higher then that and you will be flushing too frequently to try maintain that level (at least once an hour). I can run 45 gallons through mine before I need to flush and usually shoot for a 60:40 ratio of permeate to concentrate .

As far as flushing, it should be done with 10 gallons of permeate and needle valve wide open at the following times, before you start each batch, after each 45 gallons of sap and at the end of each run. The peroxide flush only needs to be done once or twice a week if you are flushing regularly to keep things clean.

Another VERY important thing that I learned the hard way that I will pass on. Change your pre filter very frequently, every day or two. It plugs up and will start to ferment very quickly and contaminate and foul membranes. And if you are not using the RO for more then a day take the filter out and throw it away. If you leave it in there it will become nasty bio stew very quickly.

I had a lot of trial am error with this RO last season but if you keep this stuff in mind you will be extremely happy with it.

Any more questions I will be happy to answer.

[SDdave]

Clinkis,

Thanks for that speedy answer. It answered all my questions.

SDdave

[Greenthumb]

First use yesterday had sap going from 2% to 8%. Did back it off and am about 6% so I wouldn't foul the membranes. Only problem is I have a leak where the quick connect fitting goes into the pre filter housing. Don think the threads are the same have to,work on it. Hope,to make first batch of syrup with this sap today here's some pics. 92049205920692079208

[SDdave]

Had the same problem. I tefloned (sp?) taped the fittings then screwed in. Leaked real horrible like. I ended up over tightening the plastic fitting and snapped it off. Replaced it and did not use Teflon this time and no leak. Hope that helps.

SDdave

[Greenthumb]

I will,give that a try. I have pipe dope on them right now

[jakeleveto]

I just wanted to post and say thank you guys for this thread, I was able to build one myself using the 8800 pump and three 150GPD filters. I set it up with the first two in parallel and the third one in series after the first two, I wanted a higher throughput than three in series but I also wanted a higher concentration percentage than three in parallel. Plus this way flow should be about even between all of the membranes.

I ended up using all 3/8th tubing except the end with the needle valve, this is because that's all the plumbing store had in stock when I went to buy fittings/tubes. I also didn't know any better so I bought all compression fittings, which I regret because it's going to make modifications much more difficult. Quick connect would have been easier. I also had some leaks until I really cranked on the fittings, but now there is only a tiny leak where I stripped out one of the RO housing ports (be careful, it's easy to do!).

All and all though this has been great for my 180 tap/vacuum setup. I was drowning in unboiled sap until I got this thing going, it's finally let me catch up. I can process a 25 gallon tank in two hours which I do several times during the day, then at night I connect it to my 55 gallon tank and let it run overnight. It's in an insulated shed but if it dips into the 20's I turn on a small space heater.

Pictures to come later, I started mounting everything on a small piece of plywood but I need some extra 3/8th tubing and a pressure gauge to get it how I want it.

[jakeleveto]

Just a follow up on this, what do you think the limiting factor of this system is? If I wanted to improve throughput next season should I add some more filters, or another pump? I'm thinking if the 8800 pump can handle it I'd like to put another three membranes on in the same order (2->1), would this double my throughput or would the pump not have enough pressure/flow to push it through?

[hodorskib]

There is only one way to find out and that is to give it a shot. I am currently running 4 150gpd membranes in series and I have 120psi at the 4th one so I imagine you can go to at least 5 or 6 but at that point you would be looking for a faster rate of process rather than a higher concentrate. These residential membranes foul quickly with concentrates when you get near 9%. At 8% and the ability to process up to 120-130gpd is all I could have asked for with my backyard operation.

[Burnt sap]

Bizrate has this unit for sale. iSpring 300GPD Commercial Reverse Osmosis Water Filter with 20" FILTERS and Booster Pump seems like the same thing you guys are building all in one unit? Would this work?

[hodorskib]

If this is the model you are referring too (http://123filter.com/catalog/product_info.php?products_id=164) it has a 5 stage filtration system. It is using 1 - 100gpd membrane and has several other filters including carbon which you don't want for sap. I couldn't find what kind of pump they are using but basically the system that I am using has 4 150gpd membranes and just a 5 micron house filter. I cannot say if that would work or not but I would be hesitant about using just 1 - 100gpd membrane for fear that it would foul rather quickly and you don't want to use the extra filters that come with it.

[KevinS]

If this is the model you are referring too (http://123filter.com/catalog/product_info.php?products_id=164) it has a 5 stage filtration system. It is using 1 - 100gpd membrane and has several other filters including carbon which you don't want for sap. I couldn't find what kind of pump they are using but basically the system that I am using has 4 150gpd membranes and just a 5 micron house filter. I cannot say if that would work or not but I would be hesitant about using just 1 - 100gpd membrane for fear that it would foul rather quickly and you don't want to use the extra filters that come with it.

They have a 400 gpd membrane and housing for 157 bucks. how many gallons of,for example, 2 percent sap could you run through one before it fouls?

[hodorskib]

What I have found is that I have been able to process 140 gallons of sap (it was 1.5%) through my 4 150gpd membranes concentrating to 7.5-8% and they did not foul. It is more about how much flow you can get through the membranes and how high concentrate you are looking for. Residential membranes, at least what I have experienced over the past three years, will begin to foul once you get over 8%. That doesn't mean it doesn't work it just means that you will need to flush / clean more often. Since mine usually runs while I am sleeping or at work I try and keep my concentrate just under 8%. There really is not much of a difference between 7.5% (about 11.5:1 ratio) and 8.5% (about 10:1 ratio) for the small hobby producer. For that extra gallon and half concentrate per gallon of syrup my membranes did not have any issues and required only a good flush of permeate after each run. Basically on my 2 x 3 half pint pan that is about 15 minutes longer I have to boil to make a gallon of syrup. I only cleaned after the system sat for a few days and at the end of the season when the sap started to get cloudy. Hope this helps.

[jakeleveto]

Thanks for the info. I have to admit I was getting very discouraged in mid-march being in over my head on sap, but the three membrane RO made things better and now I'm already looking forward to next fall to try a six membrane version (Two stage, 4->2, more concerned about throughput rather than concentration level) with my ~200 taps on vacuum. Between that and some improvements I have planned for my evaporator setup I shouldn't run out of firewood next spring!

[4010]

Thank you all for the useful information. This is my second year for maple syrup first year 5 gallons this year 14 gallons. This year built an ro with 2 100 gallon a day membranes and a procon 100 gallon an hour pump with 1/3 hp motor and was able to reduce my 3% sap in half. I use 2 fish fryers to boil my sap so the ro is very helpful this year. I am thinking next year I will add 1 or 2 more membranes and larger sap storage to be able to let ro run all night.

[ARKmaple]

Hi Snowy Pass Maple
I have been reading about homemade RO's all week, with the intentions to build one for next season. I keep getting drawn back to your posts. I too have a small operation with the intentions to maybe move up to 200 taps next season. It is just finding the time to boil. My issues are my sugar bush is 1/2 hour away from the house, so I can not always be on site. There is no power on site either. I can run a generator, but do not want to listen to that all day. So the idea of running a 12v system while I sleep and work sounds perfect. I am just looking to see if you would be willing to share an up to date diagram/plan or material list of what you are using. I know you have gone through a lot of growing pains and it is much appreciated.
Thanks

[Fleman202]

here pic of mine, I bought 3/4 port end caps for supply side I kept 1/2 ports for discharge
85698570857185728573

What is the capacity of your system in these pictures?

[jrgagne99]

Time to bump this thread again. :-)

[DaveB]

This thread is a wealth of information! I'm really considering building a system that will help reduce some of the sap that I collect. I usually boil 3-4 days a week so having an RO would help me. Even if it only processes 25% of the sap that I have, my calculations show that it would boost my overall sugar content and thus reduce boiling time. I need to keep costs down, like around $500, so the 150gpd system looks like it fits the bill but I'm wondering about getting a little better performance.

In looking at Bret's system (https://sites.google.com/site/mattatuckmadnessmaplesyrup/home/homemade-reverse-osmosis-system), it looks like I could process about 150gpd. I also saw mention above about 400gpd membranes and I'm wondering if I could replace the membranes in Bret's system with these membranes:

http://123filter.com/catalog/product_info.php?cPath=35_49&products_id=171

I know they are more expensive so I would initially looking at using a pair of these. I guess my question is, does the Aquatech pump generate enough pressure for these membranes or would I need another pump. If I do need another pump, what would be a good suggestion?

FWIW, my plan is to start the unit the night before I would be boiling and have it just recirculate sap from/to my 1000 gallon storage tank.

Edit: I saw on the iSpring site that the membrane needs 100psi and that they have a pump that delivers that pressure. However, I also saw that they have a complete 400gpd (http://123filter.com/catalog/product_info.php?cPath=27&products_id=1075) unit for about $600 which is about $60 more than if I price the individual components together. Can I use an off the shelf system like that? It would save me time from putting it together.

[hodorskib]

Good question I do not know enough about the 400gpd membranes other than the cost being 150 dollars each? I found the 150gpd membranes for 28 each so that is what I went with. The aquatech pump runs the 4 that I have in series keeping 120psi throughout so it may be possible. I am interested in seeing what others may think? Please post if you give it a whirl. I just set everything up and it looks like we will be in full swing here in CT later in the week with temps approaching 50.

[BIGMAPLEFARM]

hodorskib,

I built a ro following your schematic but I put in 3 pressure gauges, one before the 5 micron filter and one after and one between membrane 3 and 4, number one reads 20, number two reads 15, number 3 reads 0. getting 2% out of each line what am I doing wrong. could the pump be bad.

[Clinkis]

I built the same one. Is filter housing filling with water? Sounds like it may not be plumbed right. Can you post a pic of it? plumbing is simple but one connection out of place and it will throw everything off

[BIGMAPLEFARM]

thanks for the reply, I will post a photo tomorrow, I think my membranes are not seated properly. From what I have seen on u tube it seems that the plastic nipple on the top of the membrane should be flush with the top of the bottom housing, mine are not and I cannot push them in any further. I believe that are applied membranes.

[BIGMAPLEFARM]

It turns out that they sent me housings that were not compatible with the 150gpd membranes.

[hodorskib]

Sorry to hear you are having problems but glad you figured it out. I wish there was a local place to pick up the materials instead of having to order all online because sometimes you get the wrong things sent.

[Vermont bee works]

I saw your ro that you built and I like it . how did it work ? . I'm trying to build one this summer , but I'm going to make it run on gas . any pointers ?

[hodorskib]

sorry have not been on the site in a while. Running it on gas I am not too sure about how to do - only thing I can think of is hooking it up to a generator or a deep cycle battery - like ones used for electric trolling motors?

[huntindogg]

Built a system last year from Brets diagram and parts list, and we are very impressed! Cut our boil times way down, actually got some sleep lol!! Not changing a thing for this year except will probably have a new set of membranes on hand just in case the originals go belly up halfway thru season. We dont have power at our shack other than a generator which I hate to hear run, so we are using deep-cycle !2 volt batteries, running an inverter to take it to 110 VAC, then a transformer takes it back down to 24VAC. We have solar panels to charge the batteries back up. Works pretty slick. Thanks again Bret for all the info. Ready for winter now!!!

[jrgagne99]

Way back when I started this thread, I spoke to an engineer at Aquatec and he told me you can actually run the Aquatec 8800 on 24VDC. It doesn't need to be AC because it has internal rectification anyway. So next season, you can just connect two 12V batteries in series. It doesn't get any simpler than that!

[huntindogg]

Hey thanks! Yes that will make it even simpler:)

[DaveB]

Good question I do not know enough about the 400gpd membranes other than the cost being 150 dollars each? I found the 150gpd membranes for 28 each so that is what I went with. The aquatech pump runs the 4 that I have in series keeping 120psi throughout so it may be possible. I am interested in seeing what others may think? Please post if you give it a whirl. I just set everything up and it looks like we will be in full swing here in CT later in the week with temps approaching 50.

For next season I am going to try this with the 400GPD membranes and see how it goes. I'm wondering about the setup though. You have them in series and I'm wondering about setting them up in parallel. Being new to the whole process I'm trying to understand this a little more. With one membrane 400GPD should yield about 16GPH, correct? I know that is somewhat reduced with the temperature of the sap. If the membranes are in parallel, does that mean that would increase the output to 32GPH?

Another thing that I'm wondering about is the pressure. The Aquatec pump is capable of 150PSI but if the output is going to two membranes, would pressure be effectively lowered to 75PSI?

[hodorskib]

My math may be off a little but when I calculated the amount the aquatech pump can handle in 24 hours I came up with about 1200 gallons at standard pressure and under normal conditions (use with water). With that said you should be able to use 2 400gpd membranes. With the extra surface area you may want to try running them parallel for a higher flow rate but you may need to recirculate or run through a second pass to get the concentrate level up to 8%. There is a small set screw on the front of the pump that you can turn up the pressure to 150psi and you will be able to maintain that throughout the system setup in parallel. If running them in series I find that you loss about 5 psi as it goes from one membrane to the next but that shouldn't be too much of an issue. You will need to play with the needle valve to create the most efficient back pressure. You may also want to try and go with 3/8" tubing and fittings to allow for a greater flow over the larger membranes. I don't know of anyone who has tried using anything larger than 150gpd membranes so you are in uncharted waters and I am curious to know how it goes? Good luck and please keep us posted on your results.

[DaveB]

My math may be off a little but when I calculated the amount the aquatech pump can handle in 24 hours I came up with about 1200 gallons at standard pressure and under normal conditions (use with water). With that said you should be able to use 2 400gpd membranes. With the extra surface area you may want to try running them parallel for a higher flow rate but you may need to recirculate or run through a second pass to get the concentrate level up to 8%. There is a small set screw on the front of the pump that you can turn up the pressure to 150psi and you will be able to maintain that throughout the system setup in parallel. If running them in series I find that you loss about 5 psi as it goes from one membrane to the next but that shouldn't be too much of an issue. You will need to play with the needle valve to create the most efficient back pressure. You may also want to try and go with 3/8" tubing and fittings to allow for a greater flow over the larger membranes. I don't know of anyone who has tried using anything larger than 150gpd membranes so you are in uncharted waters and I am curious to know how it goes? Good luck and please keep us posted on your results.

I've been racking my brain trying to determine what I want to do because I have a personal need and a business need. Then there is consideration of the most effective cost per GPH. Even if I went with the Aquatech pump I'm looking at about $600 but for about twice that I can get a nice unit that can do about 5 times what the Aquatech can do. That would suffice for me and be good for someone that might want to rent it from me. I do like the flexibility of the smaller units though. It's certainly an option for someone looking for 16-20GPH of concentrate.

[hodorskib]

When in doubt always go bigger you won't regret it.

[llew.williams]

Built a system from hodorskib plans. Just ran my first test with some sugar water. Can't wait to try it out on some real sap. I turned up set screw on pump (Aquatec 8800). Can't get it above 103 PSI. It was set at 80 out of the box. Any idea what is going on?

[mellondome]

Restrict your concentrate outflow from the membrane

[Clinkis]

Restrict your concentrate outflow from the membrane


With these RO's restricting flow will only allow you to get to around 100psi.
Aquatech 8800 pumps have pressure releif so only way to get pressure higher is to adjust Allen screw on pressure releif valve which it sounds like you already did. Perhaps you need to adjust it more. I used to have this same RO and could usually get it up to around 120psi if I remember correctly.

[sugarphil]

I've been racking my brain trying to determine what I want to do because I have a personal need and a business need. Then there is consideration of the most effective cost per GPH. Even if I went with the Aquatech pump I'm looking at about $600 but for about twice that I can get a nice unit that can do about 5 times what the Aquatech can do. That would suffice for me and be good for someone that might want to rent it from me. I do like the flexibility of the smaller units though. It's certainly an option for someone looking for 16-20GPH of concentrate.

Like I stated on my post for an RO under 300$, I suggest you look up on ebay for carbonator pumps/motor assy, for a little over 100$ you could probably get your hands on a use procon pump coupled to a suitable motor and it would certainly come with pressure gauge and some other cool bits (pressure regulator, appropriate fittings, etc...)

good luck and keep us posted with the setup performances

[llew.williams]

Dumb question?
This is my first time using quick connects with 1/4 tubing.
How the heck to you get them to disconnect without destroying them?

[sugarphil]

you should be able to push the small white ring at the extremity of the fitting while pulling on the tubing. Tools exist to do it but you could use a open rench key that would fit snugly over the 1/4in tubing or design one out of wood that will go over the tubing and help press the small ring all around.

12399

[llew.williams]

Just fired up new RO. Got my pressure up to 120.
Getting 2% sap. After RO I'm seeing 4%.
Thought I might do a little better.

Question: I know I will need to clean with hydrogen peroxide solution. How often do I need to do that?

Tapping more trees tonight. :) I'm firing up evaporator tomorrow. :)

[llew.williams]

RO working fine. I'm getting the hang of it. % up to around 7.
Thank you Matttuck Madness for the plans.
Fired evaporator yesterday for first run.
Excellent.

[JeremyFXDWG]

I am a new to this so I apologize if this is a dumb question...

What is the advantage of running multiple "Home" grade membranes over a single extra low energy membrane? I am thinking of doing just the single 2.5x21 extra low energy membrane that is rated for 330GPD. When I factor in the costs of all the housings and fittings it is the same cost as doing multiple smaller membranes. I am also not looking for maximum production as this is just a hobby so simplicity kind of wins for me.

I am thinking Aquatec Pump -> a 1 Micron filter -> 2.5x21 Extra Low Energy Membrane and that's it.

Thanks,
Jeremy

[Daveg]

Thanks for the ideas, sugarphil!

[hodorskib]

RO working fine. I'm getting the hang of it. % up to around 7.
Thank you Matttuck Madness for the plans.
Fired evaporator yesterday for first run.
Excellent.
You are very welcome and I updated the site with a video that shows things a little more clearly.

[hodorskib]

I am a new to this so I apologize if this is a dumb question...

What is the advantage of running multiple "Home" grade membranes over a single extra low energy membrane? I am thinking of doing just the single 2.5x21 extra low energy membrane that is rated for 330GPD. When I factor in the costs of all the housings and fittings it is the same cost as doing multiple smaller membranes. I am also not looking for maximum production as this is just a hobby so simplicity kind of wins for me.

I am thinking Aquatec Pump -> a 1 Micron filter -> 2.5x21 Extra Low Energy Membrane and that's it.

Thanks,
Jeremy
I have thought about that as well but I do not know enough about the larger membranes to give you any specific answer - sorry, as for the 1 micron filter I was told by numerous people that a 1 micron is too fine for the purpose of processing sap to stick with a 5 micron. If you do go with the larger membrane please share your results.