Re: Overflow boxes and freshwater

["Tom Wood" <tomwood2 at flash_net>]

My tank has an in-tank sump that was created by dividing off six inches of
one end of the tank with a piece of 1/4" thick black acrylic. The acrylic
has a notch cut in it at the top edge to create an overflow. I glued on some
acrylic brackets on the tank side that lets me slip in a variety of
prefilter materials. At present, I use a piece of black plastic eggcrate
with 1/2" openings that is long enough to cover the entire overflow. In the
past, I've had to double up the eggcrate and offset it so the openings
through the two layers were 1/4". Even that didn't stop a new batch of
Cardinal Tetras from slipping through, so I wrapped it with black fishnet
until the Cardinals were fattened up to the point that they couldn't get
through. At some point the second layer broke off, but now the fish aren't
interested in the overflow, so they don't go through it any more. I have a
fish net in the sump side so any fish that does get through is still caught
before going through the entire filter.

TW