My LPS and Leathers are bleaching/losing color. Please Help

[Reefer140]

Hey everybody, over the past week or two my corals have all been losing their colors. Starting with my purple fungia and frogspawn which have both turned like a transparent colors. Now the problem has pretty much taken to all my other corals... all of which are lps and leathers... any ideas

My bulbs are about 7 months old (VHO)
Ammonia - 0
Nitrite - 0
Nitrate - 15-20
Ph - 8.2
Alk - 11

 

[naturebatslast]

What's your Calcium level at and how are you dosing for alk and Ca?
How often are you changing water out?

 

[cujo6984]

whats your temp?

 

[alpha0r]

Is your ro/di still working correctly?

 

[sbertomen]

fwiw - when I notice that my colors are a little faded my Mg has always been too low, never got 'transparent' though. Probably worth checking.

 

[JayM]

nitrate looks a little high for happy corals, but unless there's another stressor like high temp, it shouldn't be the primary cause.......

 

[stingythingy45]

What's the salinity?