I have a 60g with a Red Devil also. I am running two HOB filters and I have a powerhead for some current low down where all the crap tries to settle. The only other things I have are some gravel for him to play with and some snails. He's about 9" long and so far it has been working well. Id say get another filter and test water. I also like having two or more filters incase something breaks and so that you can clean one at a time and not worry about spiking. How big is your guy?