I put a clay flower pot in my so that the fish could have a place to hide.

Also buy a copper test kit to make sure your level is where it needs to be. Since you are running a bare bones filtration system, weekly water changes are a necessity.

Another thing I did was keep 1-2 mollies in the tank just to keep the biologicals in the bio-wheel going between times I had fish in the QT. Mollies are brackish water fish and do well in a hyposalinity tank.

Gary