I've got a 40g breeder style tank that I've got a school of cardinal tetras, rummy nose tetras, zebra danios, celestial danios, and a single Kribensis in. Now I know that Kribensis and Apistos are suppose to be nonaggressive fish and are good for communities, but my question is if I could mix a single Krib and a single Apisto together in the 40g?