I have one red-tailed shark, five gold barbs, four rosey barbs, four white-skirt tetras and three emerald cories in a 29 gal tank that has both an undergravel filter as well as two power filters (one w/ just a sponge for biological filtration). How many, if anymore, fish can I cram into this tank, and can anyone suggest breeds? I can't go to a large tank yet since I live in a second storey condo.