Well the other 5 are all doing well so I really didn't think the sand had a lot to do with this problem. Also after talking to other discus keepers on my local forum, others have had very similar problems with blue diamonds. I don't know if it is the variety or what. One of my golden phoenixes hides a lot but that's becuase it is getting picked on by the other one but it is still eating.
I can remove the sand if I have too, I personally don't like bare bottom tanks and I find it makes fish skittish, but if it will help I can do it.
I also recieved a message from the lfs I got these fish from. I had informed him (the owner) of the problem I was having with this one fish and that the others were doing really well. He got back to me tonight and said that if I wanted to I could bring back the one I'm having trouble with and switch it for another one. I'm thinking this might be a good idea, what do you think?