green water

I agree, 15 hours a day is way to much. I forgot to ask about the sun light. If your tank is in front of a window that gets direct sunlight + running your lights for 15 hours will cause the water to turn green

 

ok so how do i make my tank not green

 

bump

 

kill your lights for 3 days and do like a 50% water change. Wait a week, and if your water is still green, then do about a 25% water change.

If your tank is getting direct sunlight, then you need to prevent that.

My blues lights come on at 12:30 and go off at 9:30, my whites come on at 1:00 and off at 10:00. That's just an example with mine. some people have theirs on for a little bit longer.

 

but if i turn the tank lights off for 3 days wont it kill my coral

 

bump

 

No, your coral would be fine without light for a few days.