>I'm a hobbyist with multiple tanks, and one of my future projects is to
>make all of the tanks a recirc system utilizing a fluidized bed. The
>maintenance would be greatly simplified, and I think I could built it
>inexpensively. The pump to push the water would be the most expensive item,
>and that wouldn't be very expensive.
I don't know too much about fluidised bed systems although I know that they
are being using in some high intensive aquacultural facilities. I have given
much thought in establishing an automatic water change and refilling set-up,
mainly to reduce the time it takes to do all the water changes in my tanks.
Adrian R. Tappin
"Home of the Rainbowfish"