get a rena smart heater they can connect to rena filters and the outside doesnt get real hot. or you can use pvc and drill holes in it. also i think rena makes an adapter to hook on to other filters im not sure if this is true as i have mine hooked up to an xp. but you might be able to find out. pvc drilled is the easiest and cheapest just make sure you sand it down a little afterwords to smooth the drilled holes and get the loose plastic off.