I was hoping to utilize a dhp in my tank. I know the recommendation is the dhp to be 12 inches away from a basking spot. However, 20 long is only 12" high. I can extend the height from the top and make sure the height of my hide is only 6" (so it would be 12 inches from hide top to dhp). Would this work or would the dhp loose effectiveness being extended away from the tank. I already have the bulb and the dimmer. I can't afford a new tank at the moment however.