virangos
03-03-2003, 5:54 PM
I know that some years back under gravel filters were highly recommended for marine tanks.I am aware of their limitations but was just wondering when the thinking changed. Thanks
OrionGirl
03-05-2003, 9:14 AM
While I can't give you an exact date, the reason UGF are no longer favored for SW systems is that deep sand beds are very popular for biological filtration, and you can' t use a UGF with sand. In FW tanks, UGF are still very popular for non-planted tanks. If you're running an aggressive FO SW tank, and want to use large crushed carbon, or similar substrate, I'd go with a RUGF, and a HOb to act as mechanical filtration.