Help! Monti Cap

[aprilschutt]

I have recently noticed some algae growing on the outside edges of my monti colony. It has spread so I decided to break a chunk off and was shocked when I turned it over. Can someone help explain what is happening and how to fix it? this is a large colony and I would hate to loose it. The algae shown in the first photo looks only half as bad under my aquarium lights. I was surprised how putting the coral in regular light made it look much worse.

 

[jda]

Need some more info on the tank and lighting.

The underside of caps is usually not as colorful as the top side, but it should still be alive and have some color.