I want to put my u.v. under my tank rather then hkeep it hang off the back. Where should I place the powerhead and the return tube? I don't want it to affect the heating as it is now. Currently, the powerhead is right next to a heater, and the warm water is going into the powerhead and returning to the other side of the tank and the other heater is never going on. Also, the temp is too warm. I'm not going to lower the heaters, but move the powerhead and return tube.