i have a pair of Giant Danios.....my 4" Gt doesn't even bother them. in my 125 i have a pair of GT a Firemouth, Frontosa, 7Clown loach, Gold Nug pleco, 2 Bala shark, and no problems the Gts aren't breeding so i know that has alot to do w/ the agression level in the tank. i love my GTs and won't think of gettin rid of them