3 Things to Know About Testing Pool Phosphates

Don’t test for phosphates unless you have algae Algae need low chlorine and poor circulation to grow, not just phosphates. If your chlorine is at 1–3 ppm, algae won’t grow regardless of phosphate levels.

Only test if algae persists after balancing everything else Use a phosphate test kit or take a sample to a pool store. Numbers over 500 ppb can be a problem, but not always. The fix is a lanthanum-based phosphate remover, followed by backwashing or cleaning your filter.

Most pool owners waste time and money on phosphates Pool stores often push phosphate removal as a money maker. Unless you have green water that won’t clear after shocking and adjusting pH, skip it. Focus on chlorine, pH, and alkalinity instead.