Devils hand disease?

[johnnybravo234]

Ive had this baby for years now and Ive never seen anything like this. Ive been watching it for a few days now and its starting to get worse. The tissue seems to be deteriorating in a couple spots. I just moved it to a tank with 250 mh lighting but this is happening on the side that is recieving indirect light. There is a smaller colony below it thats growing off of the same rock that is halfway covered by the big colony and never gets all direct light so i figure the deterioration isnt from lack of light. There is no rotting tissue, it just looks kinda like hole in the head disease that oscars get. All my levels are fine.. i have lps and sps coral in the tank that is all healthy and growing and I run carbon and skim 24/7. Like I said Ive had this coral for years without any problem. Any info is greatly appreciated! Thanks. Here are some pictures:

 

[RokleM]

Shrimp/crabs in your tank? Make sure they aren't nibbling at night.

 

[Skateboarder]

Definatley check for crabs at night.

 

[johnnybravo234]

You think it looks like physical damage? The smaller one below it has been cranky lately too but it doesnt have any physical problems. Im going to test the water again tonight. What kind of effects does copper have on coral? I have a quarantine tank running copper right now and maybe i could have contaminated my main tank? I have two peppermint shrimp and there is a crab from the ocean around here that escaped from my fuge into the main display but he hasnt hurt anything so far but maybe hes been tasting the leather. I just put brand new carbon in a couple weeks ago.... this is so irritating