One of the advantages (if you don't want massive current) of a RFUG is that they don't have a large "felt" effect on tank water current. In other words, you can turn over a hig GPH through a reverse flow UGF and not wear out your fish. I usually turn over my tank volume 6-10 times an hour through a RFUG. I also run a power filter in conjunction with them. If you are not planning to run your powerheads revers, you should look into it. It is IMO a far better way to run a UGF.