Black coral branches

I have noticed that my sps bird nest coral has a few branches that are turning black and I'm not sure what it is from. I didn't notice it when it first started because it's on the back part of the coral. I willpost photos as soon as I get home. Any thoughts of what it might be though?

 

Usually that is a sign of algae growing on the tips, the birds nest may need more flow. I would also check parameters and phosphate levels.;D

 

All of my peramtors are good, as far as flow it seems good but I have been wanting to add alittle More because of some of the white cloudy fuzzy looking crap on some of my rocks. Im pretty sure its from low flow. I have a mp 10 running at full in want mode and a mag 5. 40g tank 20g sump maybe I should up to a mp 20 and use the mp 10 for dead spots if their would be any.

Hum

I tryed to post a photo but it messed up and then I had to go to work so iwill work on that tonight after work.