It shouldn't be, I use a maxi jet 1200 (also stolen from a defunct seaclone) in my 29 gallon. I have other maxi-jets in my other tank, so I had lots of spare intake skimmers and wave deflectors to put on it. If you don't have those, just make sure you have something to keep fish from getting sucked in. If you think the flow is too much for the particular area you want to put it, you can always use flexible tubing with holes in it to diffuse the outgoing water.