Homebuilt RO with 400gpd membranes

[DaveB]

where do you guys find the pressure gage. I’ve had the homemade ro for about 3 seasons now and can’t seem to find a gage that last. I’ve bought them from Home Depot and Lowe’s. Right now I’m running without one and using my hydro cup to take samples so often. Seems to be working
And I just keep adjusting the needle valve

This is the one that I ordered but I can't speak personally to it's quality because I have not used mine yet (I'm still waiting on a replacement transformer):

https://www.amazon.com/gp/product/B0124FAV6Q/

It seems to have good reviews and be a solid product but we'll see.

[DaveB]

I used my setup the past weekend for the first time and I wanted to share my experience if it would be helpful to others. The unit basically operated as expected and I'm happy about having a supply of fresh water that I've found several uses for. That alone in sugarhouse without running water is great!

I do see some leaks in the seals on the filter housing and membranes despite wrapping them with teflon tape. I think I need a wider tape and will be getting some this week to see if that takes care of the problem.

The system is running about 110psi. I don't know if that is normal or not but it seems to run there steadily.

I initially rinsed the membranes before use and then when I closed the valve on the concentrate end made sure that the water coming out the other end was clean and that the sap was concentrated. I passed 1.5% sap throught it the first day and it took it to 3%. The second day I ran 2% sap and got 4% out. The rate at which the concentrate comes out is about 7.5 gallons an hour. On the other end I'm getting about 25 gallons of water each day which is about one hour of boiling for me. That's the big savings to me. It's like having a side evaporator taking off water for me!

I did want to ask about the needle valve that others are using. I wound up buying a dial/gate valve and it works but I'm thinking a needle valve might work better. Can someone share what they are using?

[hodorskib]

I had similar problems with leaks and was able to fix them by using a thick teflon tape - https://www.amazon.com/Oatey-15100-H.../dp/B00DZV3L5C ( I had to use 8-10 wraps) and then had to use a silicone lubricant on the o-ring in order to tighten enough to get a better seal. My 3 x 400gpd system is also running around 115-125psi. I have found that in order to provide enough flow through the larger membranes it is better to back off on the needle valve and recirculate rather than try and do in one pass.

[jdircksen]

What pump are you using with the 400gpd membranes? I have an Aquatec 8852 right now using 150gpd membranes but would like to get faster processing rates by switching to 2 of the 400gpd membranes.

EDIT - disregard. found the answer in this thread http://mapletrader.com/community/sho...ing-a-small-RO

[barnbc76]

I have an aquatech 8800 it seems adequate for the task with 2-400gpd membranes. I dont really know the rate I'm getting as the first batch last week was already close to 3.5% and now I'm doing 2.5% and recirculating back into the same tank. In 5 hrs it removed about 17-18 gal of water.

[rlapointe]

This is the one that I ordered but I can't speak personally to it's quality because I have not used mine yet (I'm still waiting on a replacement transformer):

https://www.amazon.com/gp/product/B0124FAV6Q/

It seems to have good reviews and be a solid product but we'll see.

I got the same one from same place. Works fine.

[rlapointe]

Hmmm...I only see the membrane on Amazon, not the housing. I looked and looked before winding up ordering the correct housing from a seller on eBay. Oh well. They should be here on Tuesday which will give me time to put things together for next weekend.



No worries! It's educational.

I bought both together on Amazon.ca (.com should have the same)
https://www.amazon.ca/gp/product/B071FJT7J9/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1