Pet Forum / Aquaria / Marine Reef / February 2005

Is there an overflow, or is it just a 1" drain hole cut into the side of the
tank?  If it is an overflow then basically any decent size pump will do. As
it will only overflow as much as the pump puts back into the tank. I might
be wrong, but I would base it off of your water flow needs.   My tank is a
29gal. and I am using a mag5 (500GPH) pump on it now, but would like to
upgrade to a mag7 (700GPH).

If it is just a drain, that would create a siphon, and you want to put water
back in faster than it will siphon out... Well I believe that is a recipe
for disaster...  But that is just my opinion. -Chris

There is a built in overflow.