Infected zoo or just stressed?

[lazuruskfp]

I got this for almost nothing at my LFS because the tank it was in had zero chance of improving its appearance. I'm very convincing when I want to be so he gave me the 7 lb rock (picture is just of an arm of it) with 6 different colored colonies for 7$. 4 of the colored colonies have recovered, but these 2 have not and some of the polyps have a brown tinge to them.
Are these infected? stress?

and what should I do to help save them if either is the case aside from keeping my tank water perfect?
thank you in advance

 

[fishboy52]

i'm interested in comments also

 

[reefkprz]

just looks like algae growing on closed polyps to me give them a while they still may recover. I dont see any signs of bacterial or fungal infections nor any necrotic tissue.

 

[lazuruskfp]

thanks for the second opinion! I'll keep the faith and hopfully I'll have a success story down the road.

 

[reefkprz]

oh one more thing just check them over at night after lights out for any critters that may be chowing on them but about half of the yellows are starting to open and t least one orange is showing signs of it so I think oyu should be ok.