I've thought of that before... is this going to be a rock scape or planted tank.......If it going to mainly be rocks than I wouldn't worry about it..... IMO UGF's are only helpfull in tanks smaller than 55, after that the body of water can really support itself. with a good filter. If your going with planted tank they say that it inhibits the roots system, I know that eventually the roots wil create stagnate water pocket which is deadly to fish. the fish you are going to put in are gravel movers, so caution there. If any thing look into the heater coils that create a warm water uplift, the powerheads that have reverse flow are a bit pricey in LFS, I just bought a coil system by hydro for a 70 gal, that shipped was 110.00 I think, I know that after I figure the cost of the UGF and 2 aquaclear 70 powerhead it was cheaper, but I also found the coil system on sale. IMO I would stay away from a UGF in a large tank, Just gravel vac. in a 4 section method weekly and you will be fine........