Why turn brown?

[deepbelow]

My question is why do some blue in particular sps corals want to turn brown. my greens stay green and my pinks stay pink.
thanks for any info

 

[fishdoc11]

Lots of different reasons but mainly high nutrient levels, particularly phosphate and/or stress from shipping or something else like changing water params.

 

[Horace]

They will also turn brown if they dont get enough light. It could be many factors though. Not enough flow, high nutrients or low light. But high nutrient levels are probably the culprate. Anything over about .05 phosphates and you will start losing color. My tank is currently about .02 which is about as low as you can get. It was measured with a Hanna meter which is super accurate. Even those who say they have Zero likely have atleast .02 if not more.