Lol katie i know i just can't make up my mind and its driving me nuts! I don't think that the Angels will kill the Cardinal Tetras cause none of my angels have killed any of my fish. The Keyhole wrigglers were eaten My step-brother's tank got cloudy and high nitrAte levels so i took 2 of his angels and had to put them into the 55G which added stress on the Keyholes. But im gonna setup the 20G and put them in there to breed and raise the fry.