ok heres the deal, i need to take my canister filter off of my 120 gallon (stocked with 1 oscar and 4 red bellied pacus with 4 big crayfish) and am trying to spend no money. i have a 40 gallon tank, cpr over flow box and tons of gravel. i also have quite a bit of play sand. i have all the pumps and stuff just trying to figure out the best way to filter this tank without spending any money. i also have 1 gallon of 2" bio balls, i know not much but its what i got. any ideas?










