I haven't had good luck with the adhesive style UTH's, depending on the brand, that is. Cobra heat mats are pain to find locally but quite a few places carry them online. They work AWESOMELY when you can find them, plus they don't have any type of adhesive to worry about getting stuck to the tank or having to peel off if you change set ups. One thing I did with mine was to put a piece of insulation underneath them then set the tank over them, to better direct the heat up through the glass bottom of the tank rather than lose it out the bottom of the mat through the table the mat and tank sit on. Just a thought...can raise the temps pretty high, though, so keep an eye on it.