why do sps brown out/loose colour

[fishkeeprian]

Hello,

As above, what should i test for?

Thanks

[mcgyvr]

Not enough light
Too many nutrients

Browning is an excess of the symbiotic algae inside the corals..

[Scott07]

Browning out is typically due to too high nutrient levels, mainly phosphate, and/or insufficient light. The zooxanthellae are crowding towards the surface of the corals tissue to try and absorb the par that they need.

Losing color.... paling and turning white, is typically due to too much light, or corals not appropriately acclimated to a new light source or intensity. Losing color can also be caused by some contaminants in the tank.