flame angel has spot on forehead

My flame angelfish has a green/brown spot on its forehead, it kind of looks like algae but obviously isn't. I just noticed it this morning. He is acting normal and so are all my other fish. Params are good. Nitrate-0 Nitrite-0 Ammonia-0 pH 8.2 and temp. is 76. The only thing I could think of that may have caused this is last night we turned the heater down since it was really hot yesterday and today it got really cold outside so from tank bedtime last night to this morning at tank wake up the temp. went from around 79 down to 76. Please help.

 

Photo? could be nothing - they do like to bump around at times. what food are you feeding?

 

Trying to get a photo but the thing won't stay still..main food is Formula 2 flakes and pellets supplemented with Julian Spring's sea veggies and frozen brine shrimp and bloodworms.

 

After thinking he just bumped into something it has been a few days and the spot is getting worse. The first two ridges closest to his forehead on his top fin are turning the same green/brown color. Anyone ever heard of this happening?

 

Hows the little guy doing? Just picked one up this weekend myself, love the little guy! though with only 3 chromis in my tank he's the giant right now...

 

He might have scratched himself of a rock and this is a bacterial infection. It's hard to know without seeing a picture.

They are a lot like us. If we get an infection, if we are getting proper sleep, diet, and lower stress, we heal up just fine. In their case, proper water conditions and diet contribute to quick healing. If it's real bad, you might need some medication.