Re: UGH and Soil Substrates
An undergravel filter works by pulling water through the gravel and
pumping it up to the surface of the tank. If you have a substrate
additive in the gravel, you will wind up pumping IT to the surface of
the tank. I've never seen it, but I'd expect some pretty permanently
cloudy water as the substrate additive cycled through the gravel and
back into the tank and back into the gravel and back into the tank.
Justin in Savannah where people sharpen their minds by narrowing them.