DIY RO - Need suggestions and direction

[bryankloos]

Hey all,

I’m interested in building up a small RO to handle my expanding set up.

2020 should have 50-60 taps on vacuum and I’ll be using a mason 2x4.

I would like to build a small RO to cut down on boiling time and free up some hours for other late winter/early spring projects.

I like to build and have a decent understanding of RO.

Can anyone suggest sizing and a build list for parts?

All help is appreciated.

Many thanks

Bryan

[maple flats]

Before that, what might your expansion be 2-3 years out? Is the 50-60 taps your likely max?

[bryankloos]

I think the theoretical max is going to be about 75 taps... and that's assuming the neighbors let me tap their trees in exchange for some syrup.
Even if I tapped everything in sight of my property I'll never get over 100 taps.

[jrgagne99]

More questions:
1) Will the taps be on buckets, gravity tubing, or vacuum? (This has big effect on yield)
2) How quickly do you want to process the sap? If you want to process 100 gallons of sap down to say 30 gallons of concentrate in an hour, you'll want 4"x40". If you can let it run for say 12-24 hours, building something more like the RO Bucket might work for you.

[bryankloos]

Taps will be on a shureflow 4008.
I'm not opposed to running RO overnite or the day prior to boiling but if I can build something to keep up with the evaporator that would be stellar.
Id like to build something that can reliably concentrate me from 2% up to 6-7%ish.

[DRoseum]

https://youtu.be/s106bSrcfno

Just add 2nd RO membrane to this and it will quadruple your sugar content in a single pass. Worked great with a single membrane for 38 taps.

Parts list with links is provided in comments below the video.

[jrgagne99]

Two 400-GPD membranes will make 4% concentrate at about 5 GPH. Your 2x4 mason will do maybe 10 GPH. You'll need to run the RO for an hour or two before boiling, but I think DRoseum's recommendation is a good one. If you plan to expand to 100-150 taps, I think a single-post 4x40 begins to make more sense, and I have used both types.

[bryankloos]

Whats the upside of 2 400GPD vs 4 200GPD membranes?
I'm assuming the 4x200 would concentrate to a higher Brix, but at what flow?

[bryankloos]

I bit the bullet and purchased the bits to cobble together 4x150GPD system.
Everything should be here by the weekend and I'll start building next week.
I'm excited to see the fruits of my labor (and empty wallet).
Thanks for the help.
Bryan

[DRoseum]

No problem! The RO is the best thing I ever built. It really cuts boiling time and fuel usage. You should be very happy with the end result!

To answer your other question, lower GDP membranes have lower flow rates, but adding multiple steps up the concentration. You might want to consider having the first 2 run in parallel and then having the 3rd and 4th in series.

[bryankloos]

What would be the theoretical concentration factor and flow of the two options:

1. 2x150 in parallel then 2x150 in series...

or

2. 4x150 is series

All assuming the 8852 pump with a 5 micron pre filter.

Thanks.

Bryan

[carls47807]

Hey Bryan,

The 2x150gpd membranes will get you about 5gph on a single 50/50 pass (taking 2% sap to 4% sap, at 40 degrees fahrenheit). Series and parallel are going to give you virtually the same performance. The membranes will last longer in series and I would suggest plumbing in series. (The reason is that each membrane is subjected to a higher flow rate).

4 x 150gpd membranes in series should get you around 10gph on a single 50/50 pass (taking 2% sap to 4% sap, at 40 degrees fahrenheit). You could run a higher restriction with four membranes in series (like 75% permeate and 25% concentrate) and get a single pass concentration of 6 to 8% sugar (however the flow rate would be closer to 5gph).

You would be pretty close to the limit of an 8852 with 4 membranes (unless you use a low pressure feed pump or have a tank with head pressure). The 8855 is a better option and they aren't that much more expensive. You would want something close to a 400gpd rating once you get up to (or over) 4 150gpd membranes.

Hope this helps!

Carl
The RO Bucket LLC

[needmoremaples]

Parallel will process the sap faster, but require recirculation and a close eye on regulator. As sap % builds you lose efficiency which is why you can do more in parallel. In series you'll pull less water out per minute but it will be a one shot deal. Pm me if youd like more info. Assuming you are building your own from the mattatuck madness plans? That's great info and easy to build saving you alot of money over the RO Bucket. I did that way 1st year and then expanded to a parallel-ish piping setup. I now have a 4x40 setup going.

Bigger membranes increase volume.