hey keep in mind i already have a filstar x3 on this tank. my proplem was getting the top of the water clean. i had a cpr overflow box laying around so this is what i did. the over flow runs into this tub with some filter wool (i believe its called) and then some bio balls. it then trickles out into the tank, where it is pumped back to the tank by a rio that pumps 640 gallons with no head i believe. you'll notice in one of the pics there is an airline t'ed off that helps out the water lifter hooked to the cpr box. all i needed to do was clean the top of the water but ended up doing this, let me know what ya think. i also included a pic of the tank so ya could see why i am trying to filter the water so much. the 4 red belly pacus!
(mines 18").