DIY RO/DI system

[Coral Keeper]

Hey everyone, so I have one 75gall per day 4 stage RO unit I used to use for drinking water and one 75gall per day 6 stage RO/DI unit for my reef tank, both were purchased from The Filter Guys way back then, then 2 more 10" RO/DI canisters. My city water isnt too dirty, cold tap runs at about 50-70 ppm with a running PSI of 55-60 or so...

I wanted to take both units completely apart, buy a few more additional parts to make one really nice water saving unit with as low waste ratio as possible.. now, I was wondering what parts I would have to buy/upgrade to make this happen and what additional stages I should have? Is 55-60 PSI enough to run 2 membranes?
Wanted to run something like this? :

Booster pump (if needed?)
1st stage 5 micron sediment filter
2nd stage 1 micron sediment filter
3rd stage Chloramine removal media
4th stage Carbon Block
5th stage Carbon Block/Matrix
6th stage Membrane
7th stage Membrane
8th stage Color-Changing Deionization Resin
9th stage Color-Changing Deionization Resin
10th stage Color-Changing Deionization Resin

 

[High ICP]

I think with a 10 stage filter like that, you end up with water vapor at the end

 

[Coral Keeper]

Bump

 

[KStatefan]

I would move the booster pump to before the membrane.

 

[Opus]

Does your city water have chloramines? If not, you are over doing the pre-filters. They are not going to do anything for the efficiency of the unit, they are there to protect the membrane(s). If no chloramines I would just stick with a 1 micron sediment filter and 1 good carbon filter (2 if you are really worried about chemicals in your water). Also why 3 DI filters? 2 is enough unless you are separating out cation and antion in the first 2 and mixed in the 3rd.

 

[TriggerFinger]

That seems like an awful lot of filters for relatively low TDS source water. My initial TDS is upwards of 200 and I run a 75gpd 6 stage BRS deluxe plus system. I get 3-5 TDS from the single RO membrane and I’ve used about half of 1 DI canister, I’ve made about 150 g of di water. I also have 75psi coming in the basement where I’m hooked up to a dedicated spigot. I really don’t think you NEED all that filtration but it’s not my choice. Also, I don’t know that 50psi is strong enough to push water through all that?

 

[Coral Keeper]

Hmm.. okay.. How do I go about making the system have less waste water? Which is my main goal here..

 

[Coral Keeper]

Hmm.. okay.. How do I go about making the system have less waste water?

 

[Bigcat39]

Get yourself a new ro membrane and housing. Get 2 big to big piggyback clips and a big bag of push fittings. Run the 2 membranes in series with the permeate of the 1st one feeding the second. I get 4 tds to the di. Double product. My ratio dropped from 10:1 to 4:1. It really works.