May be a bit too small, really. At least for adults. Just the pike and green terror may work, but both are aggressive species to start.it is 7inch GT in a 55g with 15 large Tetra (Buenos aries and colombian) he is pretty easy going but is slowly taking them out maybe 1 every few weeks. I was thinking if I drop in a good sized belly crawler now with the other fish he will be distracted and there are some good hiding places.