RO Issues

[Dk0306]

RO systems issue. My RO is putting out way more concentrate than it is water. I have a needle valve on the line running to the concentrate bucket. Even running it at 100psi, the water is barely being separated it seems. Any thoughts as to what is happening? I cannot get that 1:2 ratio

[ecolbeck]

This is an RO Bucket?

Everything is plumbed correctly?

RO was properly stored over the winter and rinsed before use?

Prefilter is new?

Best case scenario is 1:1 ratio of permeate to concentrate.

[Dk0306]

This is an RO Bucket?

Everything is plumbed correctly?

RO was properly stored over the winter and rinsed before use?

Prefilter is new?

Best case scenario is 1:1 ratio of permeate to concentrate.

Everything is setup correctly. It’s a brand new setup that I pieced together and built (however, since you mentioned it, how should you store it for the winter?). Setup is meant to run at 80psi, but if I run it at 100, it seems to put out more permeate, but still does not seem like it is drawing as much water as I would think it should. Permeate line seems to be more of a drip.

[BAP]

Either you have the needle valve closed down too much or something is not plumbed up correctly.

[ecolbeck]

Seems tough to diagnose without knowing the parameters of the pump and membranes. It could be due to a mismatch in capacities or it could be plumbed incorrectly.

[Gord]

Either you have the needle valve closed down too much or something is not plumbed up correctly.

He said his system is putting out way more concentrate than water. The needle valve is on the concentrate hose. I was thinking maybe the needle valve isn't working. I have Carl's system, although not in a bucket. I think I could literally shut the concentrate hose completely off with the needle valve.
So if he has the needle valve completely closed and it's not stopping the flow, the valve isn't working.
At least that's what I gather from his post.

[Dk0306]

He said his system is putting out way more concentrate than water. The needle valve is on the concentrate hose. I was thinking maybe the needle valve isn't working. I have Carl's system, although not in a bucket. I think I could literally shut the concentrate hose completely off with the needle valve.
So if he has the needle valve completely closed and it's not stopping the flow, the valve isn't working.
At least that's what I gather from his post.

I would post a picture of my setup on here but I have issues with the photos uploading when I go to add them. I did not use the brass sleeves that came with the needle valve, if that makes a difference or not. I took them out. Would the brass sleeves make a difference with back pressure if I inserted them into the tubing? The pressure will change currently when I open or close the valve.

[Dk0306]

Seems tough to diagnose without knowing the parameters of the pump and membranes. It could be due to a mismatch in capacities or it could be plumbed incorrectly.

I am using two 50gpd membranes and a AquaTec 8852 pump. The build I used is a DIY one someone shared. They said it is designed it to pump about 75gpd at 80psi. I ran one bucket and it separated, I would say a half gallon out of a 5 gallon bucket, maybe.

[Gord]

I'm not sure about that DK. I also have problems loading pics on this site, but my computer is old.
Here's how mine works. With all three hoses; suction hose, permeate hose, and concentrate hose all wide open in a barrel of sap, the sap in the concentrate hose, with the needle valve, is flying out at high pressure. Almost nothing is coming out of the permeate hose. Now, with the system full, I start slowly closing the valve on the concentrate hose. Pretty soon water starts coming out of the permeate hose. At this point, I have two cups lined up, one for concentrate and one for permeate. I keep closing and adjusting the valve and dumping the cups until both cups fill up the same amount at the same time frame. I also recheck this periodically during the process.
Hope that helps.

[therealtreehugger]

Make sure there is nothing clogging your intake.

[Vtmbz]

Membrane outputs are calculated at either 40 or 60 degrees, operating on plain water. RO outputs will be reduced as the sap temperature is much colder. In addition, pressed into sap concentration duty the output is further reduced compared to plain water.

That being said, a rough calculation of your system indicates an output of about two gallons an hour of concentrated sap. The output is supposed to adjusted so that both the concentrate and the permeate flow at the same rate. I put the two lines in identical quart containers. The output should reach the top of the containers at the same time. Adjust the needle valve accordingly.

[MassMapleNut]

Has this ever worked before or and it is not now, or it never worked from day one? If it worked before but not now, are you recirculating the concentrated sap into the same bucket or a separate bucket? If the same bucket, you may be getting the sugar concentration too high which reduces the efficiency of the membrane (less water in your mixture so harder to push what's there through membrange). Not sure how quick the 50GPD membranes will foul, as I use the 400GPD ones and those go for quite a while. Every so often I'll put the suction and concentrate lines both in a bucket of fresh sap and run it with the needle valve wide open for 15 or 20 minutes to flush the membranes. If this never worked from the get-go, make sure you have the lines hooked up correct. I recently updated my RO by adding two more additional membranes and wasn't paying attention. I was following an online schematic that had the output lines reversed from the membrane holders I'd bought. Took me a minute to figure out why things weren't working right, because the needle valve was having no effect on the output. lots of good youtubes out there as well on how to put one together. Just search for 'Homemade RO system for maple sap'. Also make sure you paid attention to the flow arrows when assembling things. Don't ask me why I know that.

[Dk0306]

It never worked from day 1 and I have the concentrate going into a separate bucket. Setup looks correct and was verified on another site. It still separates water, just no where at the rate I was expecting. The permeate line drips where as the concentrate is a steady flow. I am wondering if I adjust the pump to run at a higher PSI, if that will help my issue. If I run it at 100 right now, you can hear the relief kick on. But, the description of the pump claims it can run higher than that.

[Dk0306]

Membrane outputs are calculated at either 40 or 60 degrees, operating on plain water. RO outputs will be reduced as the sap temperature is much colder. In addition, pressed into sap concentration duty the output is further reduced compared to plain water.

That being said, a rough calculation of your system indicates an output of about two gallons an hour of concentrated sap. The output is supposed to adjusted so that both the concentrate and the permeate flow at the same rate. I put the two lines in identical quart containers. The output should reach the top of the containers at the same time. Adjust the needle valve accordingly.

I think the sap temperature might have also been part of the issue.

[MassMapleNut]

What type of setup do you have? Single membrane? Multi membrane? 5 micron prefilter? Where are you measuring pressure? What setup instructions did you follow? What happens if you shut the needle valve all the way off for a second? If does all flow stop from both water / concentrate lines? As you close the needle valve you should see the sap flow slow down and the water flow increase. If this is not happening, I would suspect its plumbed wrong. Is your raw sap bucket much lower than your RO setup? Those little pumps won’t lift vertically very well. I try to keep the sap higher than the bucket. With my setup I aim for a 50/50 split. For every bucket of concentrate I get a bucket of water. Much beyond that and I have have to flush it more frequently. That’s with a 2 membrane setup. I think a couple of years ago with 1 membrane I was 2:1, 2 gal of concentrate for 1 gal of water at 100PSI

[maple flats]

Where is your needle valve? is it on the discharge for the concentrate hose? it should be, not on the permeate line. It should go through your pump, then through your membrane and then be restricted out the membrane (s). The permeate should be connected to the outer fitting on each membrane canister, if more than 1, tee them together, then run that hose to the permeate bucket. Is that how your connected? The concentrate should be connected at the center of the fitting on the caqnister. If more than 1 membrane, tie the membranes together , usually at the bottom center of the canisters.

[eustis22]

does it make a difference if i run 1/4 or 3/8 piping to my 2 (series) 400 gpd MESbranes?

[Dk0306]

What type of setup do you have? Single membrane? Multi membrane? 5 micron prefilter? Where are you measuring pressure? What setup instructions did you follow? What happens if you shut the needle valve all the way off for a second? If does all flow stop from both water / concentrate lines? As you close the needle valve you should see the sap flow slow down and the water flow increase. If this is not happening, I would suspect its plumbed wrong. Is your raw sap bucket much lower than your RO setup? Those little pumps won’t lift vertically very well. I try to keep the sap higher than the bucket. With my setup I aim for a 50/50 split. For every bucket of concentrate I get a bucket of water. Much beyond that and I have have to flush it more frequently. That’s with a 2 membrane setup. I think a couple of years ago with 1 membrane I was 2:1, 2 gal of concentrate for 1 gal of water at 100PSI

Two 50gpd membranes, 5 micron prefilter. Would it be better to switch to 100gpd membranes? I got it to run better yesterday after reading everyone’s advice.

[Sugar Bear]

The idyllic question to be asked and answered here would be .... when you close your needle valve down completely, does flow from it stop completely? If not, something is wrong with your needle valve. Would bet the removal/non inclusion of the brass sleeves is the cause.

[eustis22]

it sounded to me like he had his permeate and concentrate outlets swapped....it's supposed to be the concentrate that drips and the permeate that comes out strong

[Dk0306]

[QUOTE=Sugar Bear;401589]The idyllic question to be asked and answered here would be .... when you close your needle valve down completely, does flow from it stop completely? If not, something is wrong with your needle valve. Would bet the removal/non inclusion of the brass sleeves is the cause.[/QUOTE

I didn’t use the sleeves. Should I have? I thought they were more to prevent the tube from being crushed but didn’t think enough pressure would be enough to crush it.

[Dk0306]

it sounded to me like he had his permeate and concentrate outlets swapped....it's supposed to be the concentrate that drips and the permeate that comes out strong

I have the outlets right, the bottom center outlet is permeate on my housings and I have those y’d together and the outer outlet ran back to the top of the next membrane than the needle valve on the outlet for the concentrate of the second housing. I got it to work a little better yesterday. I do have a questions about membrane question though. I use two 50gpd, I just purchased two 100gpd. Will those improve the performance/speed of the RO?

[maple flats]

Part of your issue is that people ask you questions but you don't answer the question. Please answer questions, rather than just you asking new questions.
Also, try again to post a picture of what you have, I think it may have been fixed. If that doesn't work, send me a picture to: dave@cnymaple.com and I may be able to get the RO working properly. With the picture it will be a big help if you indicate where the flow is going, the in and out of each and where the needle valve is. Believe me, we ARE trying to help.

[Dk0306]

Part of your issue is that people ask you questions but you don't answer the question. Please answer questions, rather than just you asking new questions.
Also, try again to post a picture of what you have, I think it may have been fixed. If that doesn't work, send me a picture to: dave@cnymaple.com and I may be able to get the RO working properly. With the picture it will be a big help if you indicate where the flow is going, the in and out of each and where the needle valve is. Believe me, we ARE trying to help.

I am not arguing or anything. Trying to answer everyone’s questions as best as I can. I am in my second year so still new to this and understanding everything. I have previously responded and mentioned what I am using, how I have the membranes and flow setup, the needle valve is on the outlet of the concentrate line going into the concentrate bucket. Flow goes from the pump, to the micron filter, to the gauge and into the first membrane, then I have the concentrate line ran back to the second membrane. The permeate lines are y’d together and go in to the permeate bucket. I will try to post a picture of my setup again.

[Sugar Bear]

[QUOTE=Sugar Bear;401589]The idyllic question to be asked and answered here would be .... when you close your needle valve down completely, does flow from it stop completely? If not, something is wrong with your needle valve. Would bet the removal/non inclusion of the brass sleeves is the cause.[/QUOTE

I didn’t use the sleeves. Should I have? I thought they were more to prevent the tube from being crushed but didn’t think enough pressure would be enough to crush it.

I am not sure, but I used the sleeves on mine and it works like a dream sent to me directly from god himself.

The bottom line here is very simple. If you can't close down your needle valve so that not even a drip comes out. Your needle valve is not working. If it does shut down then open it to the flow rate you want. 1 to 2 or 1 to 3 ... concentrate output rate to permeate output rate are the standard ballpark settings.

[DRoseum]

I have the outlets right, the bottom center outlet is permeate on my housings and I have those y’d together and the outer outlet ran back to the top of the next membrane than the needle valve on the outlet for the concentrate of the second housing. I got it to work a little better yesterday. I do have a questions about membrane question though. I use two 50gpd, I just purchased two 100gpd. Will those improve the performance/speed of the RO?

Yes going to larger membranes will increase the permeate rejection rate. Two 50 gpd membranes is going to be VERY slow.

In general those membrane will perform at about 25% of their rating at 40F for sap. 50 gpd ==> 50gpd/24hr/d x 0.25 = 0.5 gallons per hour of permeate. That's very slow. 2 combined will give you 1 gallon per hour.

What pump do you have? Go to the largest membrabes you can buy for the housings and pump you have. Link below has 10% discount codes for 150 gpd and 400 gpd membranes.

https://www.roseummaple.com/2021/12/discounted-ro-membranes.html

Link with overview of RO basics for building small hobby RO units

https://www.roseummaple.com/2020/01/diy-2-stage-portable-hobby-ro.html

[Dk0306]

[QUOTE=Dk0306;401597]

I am not sure, but I used the sleeves on mine and it works like a dream sent to me directly from god himself.

The bottom line here is very simple. If you can't close down your needle valve so that not even a drip comes out. Your needle valve is not working. If it does shut down then open it to the flow rate you want. 1 to 2 or 1 to 3 ... concentrate output rate to permeate output rate are the standard ballpark settings.

I will put the sleeves in to see if it makes any difference. I have not had a chance to run it the last couple of days, but when I last used it I do believe I shut the valve completely and the flow stopped.

[Dk0306]

Yes going to larger membranes will increase the permeate rejection rate. Two 50 gpd membranes is going to be VERY slow.

In general those membrane will perform at about 25% of their rating at 40F for sap. 50 gpd ==> 50gpd/24hr/d x 0.25 = 0.5 gallons per hour of permeate. That's very slow. 2 combined will give you 1 gallon per hour.

What pump do you have? Go to the largest membrabes you can buy for the housings and pump you have. Link below has 10% discount codes for 150 gpd and 400 gpd membranes.

https://www.roseummaple.com/2021/12/discounted-ro-membranes.html

Link with overview of RO basics for building small hobby RO units

https://www.roseummaple.com/2020/01/diy-2-stage-portable-hobby-ro.html

Great, thanks! I have the aquatec 8852. Says it is meant to handle between 100-200gpd ro systems.

[DRoseum]

Great, thanks! I have the aquatec 8852. Says it is meant to handle between 100-200gpd ro systems.

You can run at least 1 400 gpd membrane using that pump, perhaps 2. I used that pump and a single 400 gpd setup very well. Also went to three x 400 gpd system using that pump. Worked, but was running at higher recovery rates than what is best for max membrane life. Later upgraded to bugger pump and added 2 more membrabes. Works great.

50 gpd is way undersized.

[RedMapleCreek]

D. Roseum,

You have a very informative website on hobby ROs. One question regarding your very nice diagram of your 5 membrane in series system. The 4 lpm flow rate of sap into the first membrane appears to be inconsistent with the 2.6 lpm flow out of the booster pump and the 1.25 lpm flow of concentrate from the last membrane along with a flow of 1.25 lpm of permeate. It appears you are achieving a 1:1 ratio of permeate to concentrate, not 2:1. Your ratio of sap to concentrate and sap to permeate is 2:1. This would be without the recirc line operating.

[DRoseum]

D. Roseum,

You have a very informative website on hobby ROs. One question regarding your very nice diagram of your 5 membrane in series system. The 4 lpm flow rate of sap into the first membrane appears to be inconsistent with the 2.6 lpm flow out of the booster pump and the 1.25 lpm flow of concentrate from the last membrane along with a flow of 1.25 lpm of permeate. It appears you are achieving a 1:1 ratio of permeate to concentrate, not 2:1. Your ratio of sap to concentrate and sap to permeate is 2:1. This would be without the recirc line operating.

You are correct! Thank you for catching those typos. Will revise that. It should be 2.6 lpm going into first membrane and the ratio is 1:1 of permeate to concentrate without recirc.

[Dk0306]

You can run at least 1 400 gpd membrane using that pump, perhaps 2. I used that pump and a single 400 gpd setup very well. Also went to three x 400 gpd system using that pump. Worked, but was running at higher recovery rates than what is best for max membrane life. Later upgraded to bugger pump and added 2 more membrabes. Works great.

50 gpd is way undersized.

I used your code to order 1 400gpd and housing. Never knew how slow 50gpd would be. I found this DIY setup on a different forum and bought all the parts they used. 400gpd sounds more like what I need for my little hobby operation (17 taps). Built this RO because this hobby also falls in a month with a lot of busy family events so I really only have one good day to boil and some evenings during the week. Thanks for your help.

[DRoseum]

Anytime! Yes 400 will work good for your size. Enjoy the season and all the activities!

[eustis22]

Some questions, doc, after my first (and probably only) test ROing

8852 aquatec pump feeding into 1 400 GPD membrane.

just under 2% fed inb

first run = just at 2% out at 100 psi

reran concentrate thru, got to 2.5% at 115-120 psi

This seems like an issue?

Would a second membrane in series increase that pct? I wanted to get to at least 4% if not 5% like I did when I ran 4 150 gpd membranes in series.

[DRoseum]

Are you able to share a picture of your setup? You should be able to adjust the needle valve on the concentrate outlet line to get an equal amount of flow coming out of both the concentrate line and permeate line.

You can always add another membrane in series (like one of your old 150 gpd membranes) but something seems off with the performance you are reporting and adding a 2nd membrane won't fix that.

I've run that exact setup you have described and doubled the concentration (using a 50/50 output).

[eustis22]

try this:

https://lh3.googleusercontent.com/9YwL5G6_frBQmnzGheyKnbuwbglua_nEqBw0MNj2eeJyHwf7WA xaEORDbHxfIjBASyXEcqbhpQrWQ1nuBmh0VNkp1yEPgRHdwFdm Xablvmlvr1Qx0FrpqQeSxC4ihP1yKT8RHcu-AXQW7YBPXZpYH9rb7WIDGsBgww2TlOBMPuRwyo6KH-BWtkv9XF3XcBl14IVPBxHp0WK3ITnUikdkLLPAIrXYNQMzJqAU snUt8EeABDVILtWmGQ6BXRj7-TMUkD1XACBcqk5rM2OBnlXwW6lrnJCMP7I5XCl4nuPFmqG-uha35HNoTOSnEX9HoTUq5jUrKylwy4JKW-nc4enoijjt-yxXM-aTB4YPtnGUmcS4KPTX7l1od5-BtoXZKzTPf1DoiGW43s2W8cguxv0Wo9W3zMcVAV5ggYFFVwf5Z 8tP-1tWdrukswYDXtMQBfXmRfdCLs62QGV_wjXnu05Fv4LzHByzxOt j40B_PzujCw3E5ISumE8c0UWc4sk258DBiXKKSWd-71eyOaTNpgf0ofjdOM5gg8hiLUuCwnt284E8nlPQGXZy5E9MPj i0TB2kC7ERDshgyXVaY8Ps-GzQcv84N_WhxvxsKmxTau1Ag5MNqX4oHcKE76DZRWmTa8SMbfQ I5qFhXIrD_Xw8buYbH9z8RcMKaiR7cpEMHf6Wmubn03ezQ0JPo fk-X2tG-QgGwpGMVpugmdMTfp48EU3BOSQ5EQ=w823-h618-no?authuser=0

[DRoseum]

How much permeate flow are you seeing?

Did you double check membrane installation and that you have the permeate/concentrate lines correctly identified?

[eustis22]

the ratio of permeate to concentrate looks like 1:2

I have the concentrate line out the left, permeate line out the middle.

[DRoseum]

Can you adjust needle valve to balance the flow so it's equal out of both?