Worried about Pl*co

I'm a bit worried about my gibbicep pl*co. He was in a 6 gallon tank and I had to move him to a 15 gallon (was planning on doing this anyway but the fact that the 6 gallon broke made me have to do it before the 15 gallon had a chance to cycle).

When he was in his 6 gallon I noticed that he had a hole in his dorsal fin. It is slowly healing, although not nearly as quickly as other people have reported having their plec's fin heal.

What is more disconcerting is I keep seeing this white film-like substance on his body. It'll be there and then it will disappear. I actually think I saw it fall off of him this afternoon...almost like he was shedding. Then he'll be normal color for a bit and then it'll be back.

Could this be his slim coat? The water conditioner that I'm using "Stress Coat" by API. It says that 12 drop/gals can be used as a water conditioner and 24 drops/gal can be used to help repair skin damage and facilitate the slim coat. Since I have been concerned about the hole in his dorsal fin I've been using the 24 drop dosage, so could he just be overproducing a slim coat?

I just don't really know what to make of it. I've noticed this before, generally after I do large water changes (I had to after I went on vacation a could times), but it usually goes away rather quickly and does not return.

thanks in advance for any help you all can offer

i know how big he's going to get...this tank is just temporary.

I'll try to find my camera tomorrow and get some pics of him

ok so here are the best pictures I could get:







The white layer I was talking about isn't as apparent in these pictures as it is at other times. Many times it is much whiter, but I think you guys can get the idea from these pictures. Like I said, it comes and goes.

Any thoughts??