What can cause color loss?

[pennyguy23]

I have a couple of nice blue pieces that are turning brown and the same with my green monipora it is also turning brown. What can I do to prevent this? They are at the top of my tank with only 150s on them. Can that cause it?

[taflaw]

SPS corals come in all kinds of colors but can change dramatically depending on the environment. For example, A green Acropora coral at the dealer may well turn out brown after it has been acclimated to your aquarium. And vice versa, a brown coral may turn out green after bringing it home.The color of a photosynthetic coral is dominated by the amount of zooxanthellae in the tissue. The higher the number of zooxanthellae in the tissue, the more brown the coral is. The extreme of this is when a coral bleaches, it goes white as all of the zooxanthellae has been expelled from the tissue. Color will vary depending on the lighting conditions in your aquarium. Actinic lighting or metal halide lighting heavy in the blue spectrum will enhance your corals' color. However, the color and health of your corals is also dependant on maintaining near perfect water quality in an established reef aquarium, with high pH, calcium and alkalinity levels, and maintain extremely low phosphate and nitrate levels as well.

[reg828]

pennyguy, what kind of lighting do you use and kelvin? sometimes if the light is too strong, sps will turn brown. also, like taflaw said water par. may affect color. also, with higher kelvin rating, specially metal halide like 20k, will show intense color in corals

[shelburn61]

Brown means your zooxxanthelae are multiplying, most likely from excess nutrients. what are your NO3 PO4 levels? Time for a water change.