thanks.. is one layer of jap mat enough BB as a bio filter?

any idea of the flowrate for those large HOF you mention? :confused:

The black box type. I m keep goldfish in 3 ft tank wit 2 big sponge filters. More aeration. Jus wash the sponge whenever dirty n siphon the waste oso ok.

thanks bro for the input.. how often you do WC running on sponge filters? you refering to those driven by bubbles right? :)

i just visited nanyang seaview to get ideas (inspiration :P) on filters for my tank.

i'm thinking of getting a dolphin 3ft black box OHF, inside put jap mat and wool. And also a plastic corner filter (guppy brand) run by bubbles, inside dont put wool, but put as much ceramic rings as i can fit inside.

intending to keep 2-3 pieces of goldfish, any comments on this set up can tahan the bioload? :D