Just picked up a 1/3 hp custom sealife chiller secondhand. Looks to be in really good condition. Came with the instructions, but here is my question: It says to plumb the chiller directly into the aquarium, and not in a loop to the sump...so do I put it in between my feed pump and the display tank so there is water constantly flowing though it? Or is it supposed to have its own pump that turns on and off when needed..and if that's the case, why not loop it into the sump?