gringort@decwrl.UUCP (12/04/87)
What do folks think about reverse flow undergravel filters in marine
applications. The general concensus I've gotten elsewhere is they
can't be beat if they're done right. The advantage primarily is that
the substrate is kept very clean because water is forced thru the
substrate from the bottom up. A key element in this technique is to
use a large external mechanical filter and a large pump.
--
-joel