Water Chemistry

Phosphates and Algae Food, Explained

A pool can have perfect chlorine and pH and still grow algae fast, and phosphates are usually why. Cross Creek Ranch is a Johnson Development community with a Design Review Committee that signs off on pool and backyard plans; Weston Lakes is built around its own golf course and country club, where lot setbacks and drainage toward the course are part of the design conversation.

Open-air cabana dining pavilion with pool view

Algae's Fertilizer

Phosphates enter pool water from fertilizer runoff, decaying leaves, certain tap water sources, and even some pool chemicals themselves. They don't sanitize or harm swimmers directly, but they function as a nutrient source that lets algae grow faster than a given chlorine level can keep up with.

Testing and Reducing Phosphates

A phosphate test kit (separate from a standard chlorine/pH kit) is the only way to know the level; a phosphate remover product can bring it down, but it treats a symptom, keeping yard debris and fertilizer runoff out of the pool in the first place reduces how often that treatment is needed.