Phosphate in top off?

[brians_224]

Thanks for your time!

I think that my top off water may have phosphates in it. I have a 5 stage ro/di system. The ro/di system is hooked up to my home water supply that uses soften well water. My tds reads 0...but I dont believe its as pure as 0. I've got a terrible case of bubble algae. Tanks is 45 gallons with a 35 gallon sump. I've got a small refugium with chaeto. I feed only twice per week. I use an ASM G2 skimmer. What else could be fueling the bubble algae?

Would it be worth while to run my ro/di through a phosban reactor?

[bertoni]

Phosphate should show up on a TDS meter. Also, you could try running a phosphate test on the RO/DI water, most likely. The kits I've seen work in freshwater and saltwater. If the RO/DI needs to go through a phosphate reactor, the filter's shot.

[drillsar]

TDS should show 0 for a RI/DI if not then your filters need replacing and possibly your membrane might not be good. What kind of membrane is on the RO/DI?My RO unit usually the sediment filters go first, my tap water here is pretty bad lots of rust in water. If your water supply is from a well you will go through more filters.