PAR

Photosynthetically Active Radiation. 400–700 nm. Measured in µmol photons/m²/s.

What corals can use for photosynthesis. Typical targets at the coral: SPS 200–350 (150–500 from low- to high-light species), LPS 100–200, softies 50–100. The Apogee MQ-510 is the standard hobby meter and applies Apogee's underwater immersion correction in firmware; an in-air MQ-500 used underwater needs ×1.32.

Last reviewed 2026-09-30