[carb850]

I'm fighting some cyano and green hair algae, everyone keeps saying it is phosphates. My API phosphate test kit reads zero, but I'm told it must be wrong. That I must have phosphates if I have algae. So I start looking closer at my water supply. I have an RO/DI unit. Tonight I took these measurements.

RO/DI = 2 tds
RO = 6 tds
Tap = 78 tds
RO/DI water (in storage container) = 45 tds

I rinse my hydrometer out in the pure water storage, but I cannot believe that is changing the tds. Is something leaching out of my container? I have a Rubbermaid Brute trashcan. Some were I read it was food grade and I just started using it. Should I have cleaned it with something? Should I get something completely different?

Any suggestions would be appreciated