some times coraline bleaches under too much light without dying, have you recently changed you r lightbulbs? lack of calcium can also cause this. but it also may be dying what are your tank parameters?
The only part that is white is the algea that is close to the top. I have not changed the lights. I will check the calcium and make sure that is not the problem. Thanks
Did your water level get alittle low? I know my corraline will whiten and die if my water gets lower then normal and it gets exposed to air, happens on top of my PH's alot too.