SPS color is the result of a delicate balance between light, nitrate, and phosphate. Push any one too far and corals brown out or pale.

The color triangle

  • Light: PAR 250–400
  • Nitrate: 5–10 ppm
  • Phosphate: 0.03–0.08 ppm
Pale corals = nutrients too low. Dark corals = nutrients too high. Browned corals = light too low.

Related reef reading

Reef tools mentioned in this article

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Reef Tank Match Quiz

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Reef Equipment Planner

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Water Parameter Tracker

Log every reading. Catch problems before livestock notice.

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