i have a 85 gallon and a canister filter came with it,..some no name brand and i went to clean it out and when i put it back together it spit so much stuff outta the spray bar and it didnt seem to be sucking very good or keeping the tank clean so i had the 400 lying around and put that on and i have filters with the carbon in them but lately it seems the water is very clear,..i do water changes like every other day 50% or more but i live about a half hour away from any fish supplies so i think my carbon is alittle wore out,..i have mostly small africans with a few 4-5 inchers in there,...thanks for the help guys