When the reading is higher
Confirm the result and review food input, detritus, media, refugium, and recent changes.
Reef aquarium phosphate guide
Interpret phosphate with nitrate, feeding, export, algae, and coral response. Track repeated readings and recent care instead of treating one number as a diagnosis.
When the reading is lower
An unreadably low result does not prove nutrient starvation; consider test resolution, nitrate, and coral response.
Units and review
ppm · Content reviewed 2026-09-02. Verify urgent livestock, dosing, and treatment decisions with qualified sources and product labels.