I keep a starry night in my daughter's comm tank... the only thing hes bothered is he eats most the guppy fry. he leaves the adults and other tank-mates alone. he has grown fairly good sized since i got him ( from approx 6" to over 12"+ now) I feed the tank live blackworms once a week and enough burrow for him to forage during the week he's a chunky guy. The smaller species work fine ime, as long as your not trying to breed anything, they will eat fry. and small male guppies/endlers occasionally ( peacocks tended to do this in the past for me, zig zags where ime the least likely to eat other fish.) depending on your pleco decision I would also be wary of the more territorial species ( I had a flash pleco who I would have never kept with a eel, as he would chase anything that neared his driftwood peice.) Mine has done fine with clown loaches and other bottom feeders as well.