Phosphate cross contamination

[Daniel225]

So my tank it’s at 1ppm phosphate and tap water sits at 1ppm I tested my fresh ro water comes back at 0ppm but I clean my filter socks with tap water and let them dry before replacing with other filter sock my question is would this cause the phosphates to leak into my tanks water witch I I know the answer to and should rinse in ro water after but wouldnt the phosphate in tank be lower than tap water as it would be diluted when added to tank no?

 

[Randy Holmes-Farley]

That small amount of fresh water is no concern from a phosphate standpoint. I'd wring them out or rinse them for other reasons, such as copper.

Small amounts of tap water are not the main driver of phosphate. Foods are.

That said, the dilution argument is not entirely correct either. Ih that water was salt water, it would be true, but since it is fresh water, it is acting like some extra top off for evaporation, which adds to the phosphate level in the tank after salinity is controlled by evaporation.