Used RO -- waste water milky?

[matt99eo]

Got a used coralife RO system with a used tank I bought. This is my first RO system.

Should the wastewater be milky in color?

[Duff Man]

No. I would replace the filters. You never know how long they really were sitting around.

[matt99eo]

I replaced the filters but not the ro cartridge. It has now been running for an hour and the waste water is clear along with the water going into my DI (water going into DI was always clear.

Am I good? How often do you replace the main ro unit?

[clockman]

Depends on how hard the water was and how often it was used. Most RO membranes can last at least 3 yrs and sometimes even 5 yrs (I didn't change my membrane until it was 6 yrs old but we have very soft water). Check your total dissolved solids (tds) in the RO water before it goes into the DI canister with one of those inexpensive electronic tds pens. If it's way over .002 ppm, you might want to replace the membrane also.