uh-oh!
yep...you did it now! hahaha
when you introduce
UNCURED rock into your tank, you kick off another cycle. Damsels are pretty hardy fish, but they still can get stressed by it.
test your parameters. I bet one of your levels (amm, 'trites, 'trates) are pretty high.
Best thing to do would be to get the fish out, and either put him in another tank, or take him back to the LFS.
If you can't do that, then you need to do some water changes. Frequently.
also, start soakin food in garlic. This will give him a fighting chance, as it's reported to boost their immune system.
Come back to us with your levels, and we can take it from there.
