Many people use the Penguin powerhead that is reversible. It comes with a sponge prefilter and I understand it works pretty well.
I think some folks also put the output of their canister down the intake. That way only filtered water goes under the gravel. Correct me if I'm mistaken here, though.
I think some folks also put the output of their canister down the intake. That way only filtered water goes under the gravel. Correct me if I'm mistaken here, though.