I have 2 reeftec pe-2's on our 360g sps tank. IMO, there is no better way to get a massive amount of flow towards the midsection of the tank. Powerheads, and seaswirls just cannot reach all the way through to the middle of a larger tank. I would think, however, that for tanks less than 6 feet in size the pE-2's would be a little excessive (kicking up sand etc..). The other drawback is how large the unit is, which some deem to be unsightly. Again, in a larger tank this is less of an issue. I have no experience with the PE-1's, but am considering putting on 2 units on the far corners. I think with tanks 4-6 feet in length these would work quite well. My husband has put a section of black eggcrate over the output where the propeller is as the units are on wavemakers and shut on and off (I was paranoid about curious fish being pureed).
HTH
