Quote Originally Posted by flameethrower View Post
This is the reason flexwatt is preferred with tubs. When using those type of heating pads you need a spare just sitting on the shelf next to the tub to tape the probes to. Other wise the tubs will not sit flat.
If you're not using a rack, it's not a problem. I glued a couple of the feet risers to the bottom, so there's air space for the UTH and probe.