Angel in a 20 gallon

[tampa]

In one of my tanks, a 20 gallon high I have a good sized angel fish. It's body is larger than a silver $ coin. Only other fish in there is a zebra danio and a bristle nose catfish. All of the (fake) plants are off to one side. What fish can I add to the tank to "liven" it up?
Thanks for any suggestions

 

[rich311k]

A school of small tetras, rummys or cardinals. Maybe 3 cory cats.