Glass Cardinal - Problems?

[naesco]

Once you have damage the opportunity for fungal and bacterial attacks sharply increases.
treat your fish in a qt.

At the same time return the rabbit fish to the LFS or sell it online, I agree that it is far to big for a very small tank like yours.

May I suggest that you research your fish BEFORE YOU BUY. Cardinals need a peaceful aquarium. Rabbit fish wrasse and tangs are active and are not suitable unless you have a very large tank.