I am sorry I did not see these responses. I have a fifty gallon aquarium with a sponge filter on a large aqueon filter and a five gallon bucket. With a male and five females. The five gallon bucket you put in lava first with a spacer between the lava rock and bottom of the bucket.Then fill the bucket up to the top with scrubby pads from the dollar store.They do a lot of pooping. Sorry for the delay.