i have an oscar in a 350 gallon pond i thought it was 300 i guess its 350 anyway he only eats the goldfish and minnnows and feeder fish, same with the gar and the arrawanna??? THE MAN AT HTE LFS showed me which to pick out so i got rainbows and monos and african mbunas but why do they not eat the other small rainbows? Small monos? Small silver dollars? I know they cannt catch a giant danio.