Lighting Issues - Bleaching
I am wondering about some bleaching we are having in our tank, and I am worried that it is a lighting issue.
We have a 90 gallon tank (48" long) that we have had for a year. I have a t5 light fixture with 4 bulbs, 2 blue, 2 white all 54watts each. The lights are on for 10 hours a day, and we just replaced the bulbs about 2 weeks ago, as we were noticing this problem, and because I know that it is recommended to replace the bulbs every year.
The coraline algea on the live rock and back of the tank started to turn white about 2 months ago, and our hammerhead coral is losing it's green colour. Also, our newest addition, a red open brain is bleaching a bit too, although I have moved it all over the tank - low, high, etc.
Do I have enough lighting? Should I have 6 bulbs instead? Could there be another issue causing this?