High Tide Aquatics

Help me add 2nd membrane onto RO/DI

Coral reefer

Past President
I have an air water ice typhoon extreme III 150 GPD RO/DI. It is cool, no complaints, but I want to max it out for output and efficiency. Soooo... I know that some people use dual online membranes, how do I do it? Put waste water through a second membrane and that's it? I'm planning on needing a booster pump anyways, I get only about 40psi as it is now so that'll help to have it bumped up. Any suggestions on what booster pump to get? Also, what membrane and housing? Is it that simple to do? I'll need to take reject water from membrane 1 and feed through membrane 2, then combine both outputs from membranes and run through the DI? or do I get a second DI for the second membrane output?
 
Shows how it can be done sort of. But brs doesn't have 150 god membrane? Too early for me. Gotta look at them later... Still font know where to get the parts from and what brand of membrane if it matters.
 
Most duals use two 100gpd. They tend to be the most efficient.

I do not know of a normal booster pump that can handle 300gpd. Even for my 180gpd I have to buy a special one.
 
So should I switch the membrane I have to a 75 or 100 to double up? Really want to conserve water and save money here. I run the filter A LOT! any other ideas are welcome
 
I called AWI about this when I was buying mine, I ended up getting the 150 on the typhoon, and a 75 on the waste water line... I can have my wife take pictures in a little while to show you...
 
Cool. I can imagine how that would be I think, hadn't thought about two different rated membranes, for some reason I thought they would have to be the same. Seems like a reasonable idea to me...do you use a booster pump?
 
I would think you'd want the larger one on the waste water line , because if you do the 150 first, its waste (assume 4:1) will be 600 gpd pushing through a membrane that can only handle 375gpd total (again assume 4:1 so 300gpd waste + 75gpd clean), so where do those extra 225gpd go? More waste than you want? Extra back pressure on the first membrane?
 
Yeah, not much new info to me, but thanks. Sounds like one guy uses three 75 gpd membranes in a row, doesn't mention booster pump, guess he had good psi to start. Maybe I just try a booster for my 150 and add a second mambrane if undetermined size and see what happens? Or maybe I try to run 2 100 gpd, or maybe 3 75s?
 
I use one of the cheaper booster pumps you can find on eBay (less than $100 vs the $200+ of "brand name" whatever the hell that means), brings my 40PSI to just over 60, when I see a drop in line pressure I know something is clogging somewhere and go to work fixing it. But then again I'm running 2 - 75gpd membranes, not 2- 150gpd
 
I completely have the opposite problem with TOO MUCH water pressure.
Have to regulate everything down.
Such a good problem to have if a reefer.
 
houser said:
I completely have the opposite problem with TOO MUCH water pressure.
Have to regulate everything down.
Such a good problem to have if a reefer.

Our friend Matt has the same issue. His toilet will sing if you don't back off the pressure. Oakland seems to have really high pressure. I think his is around 60psi on it's own!
 
sfsuphysics said:
I use one of the cheaper booster pumps you can find on eBay (less than $100 vs the $200+ of "brand name" whatever the hell that means), brings my 40PSI to just over 60, when I see a drop in line pressure I know something is clogging somewhere and go to work fixing it. But then again I'm running 2 - 75gpd membranes, not 2- 150gpd
This is the type of info I'm looking for! Thanks! I may try a bigger booster and go with 2x150 gpd if feasible, but it seems like going with 3x75 gpd will be the way to go for me. I have seen a system with the aquatec 8800 that has 3x100 gpd. Still trying to decide what booster pump is best for me
 
My water pressure issues is because I live uphill of my water pumping station, and 40psi apparently is ok for the city to get away with so I'm stuck with that, and being as I know I have copper all the way to the street it's not an old pipe issue for me. My parents in San Bruno on the other hand have something like 90PSI from the street, when we redid all the plumbing in the house we found quite a few pipes where water pushed through the pipes (with corrosion), had to put a pressure regulator on it to bring it down to 60PSI.

Man what I wouldn't give for that type of pressure *sigh*, booster pump? pshaw I'll run 5 membranes back to back!
 
I got Matt smoked at 110psi!

Coral reefer said:
This is the type of info I'm looking for!

I thought you just wanted physical help installing it (i.e. muscle?) Don't mislead me with ambiguous post titles.
 
So in contrast to what Dustin said earlier thy he uses a 150 then a 75, BRS said that won't work...either they are right and air water ice gave Dustin two 75s or they don't know as much as a company that actually deals more with RO systems...still awaiting an answer from spectrapure. I ordered the aquatec 8800 booster pump, been wanting to try it for awhile an it was on sale, and two 75 god membranes. So for now I may just replace the 150 I have and run the two 75s. Depending on the pressure I get I may add a third later. TIRED OF WASTING SO MUCH WATER!
Any tips on if I need to change out or adjust the flow restrictor if I go from the 150 to a 75? Call me stupid if you want, but I don't really understand the function of the flow restrictor...back pressure or something? Anybody link me to a good read? Thanks!
 
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