Doubling the water volume

[badflash]

Great for in doors systems, but keep in mind that grow beds do the same thing.

[dufflight]

Ha found ya! http://www.youtube.com/watch?v=_DJF3pgELXE Really cool! Just like my bioreacter with Kaldnes media, but much simpler! Great design! You could even add a ring around the unit containing filter foam, and it would give you some mechanical filtration. Add some styrofoam to float the unit, and it could compensate for fluctuating water levels. Darn, something new to build!

Thats the one. It's even my hand