View Full Version : Phosphate in my filtered water

12/11/2011, 02:20 PM
I have a 75gpd premium series RO/DI filter. When I tested my water today, it showed 0.01 tds. However, when I tested the phosphate level, it showed 0.1ppm with a Salifert kit. My lfs showed a similar result. Does this sound right? If I replace the ro membrane and/or the di, will it bring the phosphate to zero?

Buckeye Hydro
12/11/2011, 03:52 PM
I assume you mean 1 ppm TDS, right? If so, the TDS is starting to creep up from 0 and it may be starting to dump what you used it to sequester.

The consensus is, based upon the opinions of folks with much more water chemistry expertise than I have, and much more reefing experience than I have, that there won't be enough phosphate in 0 TDS water to be a concern.

If the rejection rate and production from your membrane is still good, probably no need to replace that. May just be time for a resin change out.