umm...i dont think the bgk would eat them...for one theyr'e really fast compared to it..but then again they use like electrical pulses to stun fish i think...them and elephant noses. I had an elephant nose, but i didnt have much luck w/him...both of these fish need pristine water conditions. i think the bgk w/eat ghost shrimp...i think thats what i heard..if not, i think bloodworms would work...both these fish are kinda known to not eat well at times. but as long as you DO make sure he eats a lot, he wouldnt/shouldnt have any reason to go after tetras, since that would seem like a total waste of energy to him (lol literally energy!)
HTH