[Silverfish]

Hey Steve, I have been thinking about the tidal movement thing too. Check out ozreef.org and scroll down to Water Circulation System. Seems like it could work, if you don't mind having a tall hood! I think that the tidal movement, together with random turbulence (wavemaker w/ powerheads?) would be ok. What I would really like to build is a surge device like Eric Borneman has in his book, Aquarium Corals. I have bought the toilet flush valve already, just have to put it together! ($8 @ HD) [img]images/smiles/icon_cool.gif[/img] I do like the idea of getting rid of the powerheads in my tank tho.
Later, Bruce