small/medium sized ro

[handtapper]

It seems everyone either builds a ro using 100gpd household membranes or xle4040s and others doing 1000s gpd. Any reason to not build one using 360 (or so) gpd membranes and a 1/3 hp pump? I'm assuming its because of a minimal cost difference between the two setups and everyone goes big or goes home. It seems foolish to me to build a household membrane setup and have to run it 24hrs to filter off 75gallons and can't expand it. I can't do a big one as I wouldn't have the trees/sap to even fire it up.

[maple flats]

How many taps are you doing, and how many might that grow to in 3-5 yrs.? A 360 gpd sounds like 15 gph to me. Generally that rating is for household water. Convert to cold sap and you likely lose 50%. Another thing, with sap you can't just set it and run 24 hrs non stop, the prefilter and membranes will need flushing (or back washing) and the flow will fall even more.
The 1st thing to start with is the # of gal you might need to process and go from there.
Once you use an RO you won't ever want to boil straight sap ever again.

[handtapper]

Dave thanks for the help/info. Currently its around 100 taps on a 2x4. I have received permision to tap about a hundred more if wanted. I understand it can't run 24hr. I don't know on the next 3to5 years how many more I would be tapping but a residential membrane setup couldn't handle any more than my current set up. If I could turn on the ro and have 30 gallons of sap ready to go in 2 hours that would be great. To me the 3 biggest time consumers are procuring good firewood, collecting sap and cooking. If I could collect 3x the sap, cut same firewood and spend same time in the shack making 3x the syrup that sounds worth 600ish dollars from I've seen available

[bowhunter]

I'm about the same size as you at 100+ taps. I've built a single membrane unit with a 680 GPD nanofiltration membrane (2 1/2 inch NF90) which has good sugar retention. It should do about 20-25 GPH of cold sap and remove about 75% of the water when it's operated using a recycle. If you operate it once through you can get about 20% per pass and recycle back to the sap tank. I used a lot of input from guys here on the forum along with a lot of research online. My main source of design information was Dow's RO design manual which is online. I would recommend you build something similar maybe using up to 1000 GPD membrane and an appropriately sized ProCon pump. Almost any design will work after a fashion, but some may not be too reliable or the life of the membrane may be shortened. Unless you can find a lot of used components it's probably going to cost $900-1,000 to build a unit. Membranes this size are about $200 each. In my case it's going to allow me to quadruple my capacity from 6 gallons per hour to 20-25 GPH using the same amount of wood. This will allow me to make an addition 40 gallons of syrup per year.

[Yankeeman]

I would like to know more about your homemade RO. We currently have around 200 taps and a new CDL 2x6 raised flue. I think your size RO would be just right.