ok..I'm setting up a rubbermaid today. I have an 11X23 UTH for it. The tub measures 37 inches. Here are my questions. WIth the UTH directly on the bottom, can I set this whole tub directly on a stand, or does it need to be raised to make a pocket of air? With room temp at a constant 75, will this single UTH heat the ambient air temp in the enclosure adequately? Thank you