How to Finish off TDS

[greenmonkey51]

I got a cheap RO system from premium aquatics 6 months ago and it was fine for my FOWLR, but now I'm switching things up and going to SPS. I need something to finish off the TDS I have. Tap TDS is around 300 and I'm getting 15-20 now. I'm on a well so I have a large amount of CO2 in the water. I need a solution to get the TDS down to almost nothing. DI won't work real well with the co2 without adding more barrels and stuff. Whats the best option. I don't want to get a new RO system either.

[FranktheTankTx]

Uh... adding a DI cartridge will take it right down to 0. Or you could try adding a second RO membrane. Run the waste water thru the second RO membrane and you would have less waste water and more usable RO water.

[greenmonkey51]

CO2 will decimate a DI resin. Thats why I'm asking.

[AZDesertRat]

DI is your only option. Building a chamber to off gas CO2 will extend its life. Try using Spectrapures MaxCap and SilicaBuster DI cartridges, they took my DI life from 150 gallons per cartridge to about 830 gallons per cartridge with no other changes.