In the start of june i will get a 15 gallon sump and a mag 7 (700 gph but only like 400 with the 5 foot head) for my 55. i wanted to move the community fish into my 30 and make that a predator tank, mostly i just like the look of bichirs . anyways would this be big enough for 1 or 2?? and if so would there be any space for a medium predator that lives near the surface or the middle, so i dont just have fish on the bottom. thanks