hodorskib's Small Scale RO Build

You should have water out of both lines if you have enough pressure on the concentrate side. There will be concentrated minerals in the concentrate side and should be pure water on the permeate side.

Bret, I built a pretty much a replica of your system and used it last year and loved it - thanks for the easy to understand instructions! I did commit a sin...I flushed with a couple of gallons of permeate thinking I would boil the next weekend, and the temps shot up and what I collected that week spoiled. I had the membranes wrapped and in the fridge, but somehow forgot to give them the deep clean. I pulled them out last night and noticed two things...a faint odor, and a little ice since they were on the bottom drawer of the fridge. Don't think they totally froze, but can't guarantee it. So, I doubled up on your normal end of season cleaning with hydrogen peroxide, and they look good, but just in case I ordered a new set of 4 150 gpd membranes ($31 each on amazon).

My question...given my poor treatment of the membranes should I even try them? My thought was they hopefully are clean after a 2 hour hydrogen peroxide bath and 40 gallons of water rinse and won't ruin my sap, and I can test to see what performance I'm getting and switch out if it is off, but my sap and time are both short and don't want to waste much of either...if they are shot after possibly freezing or with the sap in them all year I'll just pitch them and consider it a lesson learned.

Thanks in advance for your input!

One thing I forgot to add...I also make beer and have a wort chiller that is basically a big coil of copper pipe that you run cold water through to cool it quickly. I'm going to do that in reverse...have a wood fire under a turkey fryer pot and run my sap through the copper coils prior to the ro to warm it (I hope) to around 100 degrees. Sap in the pot of course, so I'm warming raw sap which can go into my pre-ro tank to recycle or straight into the evaporator...whichever is ahead of the other. Seems worth a little wood given the yield through the ro with warm sap vs cold.

I wouldn't toss them yet - warm up a five gallon bucket of water and 2 bottles of peroxide to about 90 degrees and let it recirculate for an hour or so. Then flush with water for about 30 minutes. Take them out and give it the smell test. As for warming the sap make sure it doesn't get too warm you will cause bacteria to bloom throughout the system. I did purchase some RO soap this year and checked the manufacturers specs on my membranes for ph levels and will be giving that a try. Will post everything after I give it a whirl.

Thanks for the tips...I'll give them a try, and it will be easy to adjust the temp on the sap...I'll just mix it with cold and play with the temps and keep it as low as I can with a high flow rate.

Brett, I hope nobody is offended, I duplicated this post. This was based on your design with input from several other folks. Here is my newly built Reverse Osmosis for sapping this year. Hoping to remove 2/3 to 3/4 of the water from my sap with this RO. Pump is an Aquatech 8852 with 3/8 outlets and is a 1200 gpd pump paired with 3 x 400 gpd ro membranes. The membranes are plumbed in parallel with a 300ml recirculation line. Hoping to process about 60 gallons of sap per hour at about 7-8%, (but hopeful for as much as 80).

I had this laid out once before, but I came across a dry sink cabinet for free. I've reorganized and plumbed it to fit the cabinet. Ill be building a cart base on the cabinet this week and hinging this to the open back.

I have about $500 in this build.

https://m.facebook.com/story.php?sto...00000295385959

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Hi Mark, nice build. You'll sure like boiling concentrate over raw sap.

I'm just a little confused about where you are getting your 60-80 GPH processing rate. When you look at the 8852 pump specs the flow rate is around 40 gph at 0 psi but drops to around 11 gph when you push it up to 130 psi which is what you will need to do to get it up to 8%. Even then you may need to do multiple passes to get it that high. Here are the pump specs. Chart is in litres per minute.
https://www.freshwatersystems.com/sp...Pump_24Vac.pdf

If I'm missing something my apologies. I'd just hate for you for you to be overwhelmed with sap if you have miscalculated.

All the best this season

May have stated that a little confusing and I may be misunderstanding something. I'm actually hoping for 15-20 gph of concentrate at 7-8%. Ill be happy if I can get in excess of 12 gph. I believe Brett had pushed his into the 8-10 range and I am hoping with added capacity to better that by a few gph. I was also told that the 8800s were 50gph. So anyway, while I have a rudimentary understanding of hydraulics, I don't know enough to make a really good guestimate, and was hoping the added capacity would allow me to max the pump and push it into my hoped for range. It will be my 1st year and definitely a learning year.



Thanks for the link to the spec sheet.

Yes the 8852 will do a little over 40 gph at 0 psi but unfortunately it drops off signicantly when you get it up over 100 psi. This is normal with most pumps except positive displacement. And in order for your membranes to work you need this higher pressure. When I was running Brett’s setup with an 8852 I was able to process 8-10 gph of sap producing 5-6 gph of concentrate. Your setup may do better but you are still limited by the maximum flow of the pump.

I may have misunderstood his original postings, thinking that when he was talking about 10 gallons per hour that he was talking about concentrate, when he was probably talking about how much raw sap he was able to process.

No matter how long it takes I will still be happy to cut my raw sap by two-thirds of its water.