corals all losing colours?

[ser_renely]

I can't figure out what has happened but my sps and rose coral, and anemone have changed from a brown-ish green to a white-ish colour. They have recently changed and had no troubles for half a year+. Two corals have somewhat kept their colour, but some is still lost. I can't figure out what is wrong.

Any one have ideas on this?

 

[seapug]

Temps, pH, Calcium/Alkalinity/Magnesium and a number of other factors can cause that. I'd do tests for pH and Alkalinity first.

 

[ser_renely]

yeah did that...roughly the same. Although ALK went from 8-9dkh. PH is roughly the same.

Just really strange. 2 things have happened that may be the reason, but both I would have thought would have affected everything in the tank.

 

[Santoki]

If all the obvious seem correct, there may be an even more obvious being overlooked. Check and double check your salinity. Have another reefer confirm your readings. If you are using a refractormeter, double check that it's calibrated correctly.

 

[ginger7286]

Has your water temp changed?

 

[guppychao]

what about new bulbs?

 

[qfrisco]

At least SPS will tend to dull or turn brown when the nitrates are too high. Did you test for nitrates?