Holding tank heating pads

[ccollins]

I'm considering installing some of the holding tank heating pads.
Question is -- the tanks are in the basement, the bottom of the tanks are laying on the underside frame/belly - they aren't exposed as I've seen
in a lot of the how-to videos

I'm concerned about removing the tank, mounting the pads on the bottom, then resintalling the tank
would it get the frame/belly too hot

another option I guess would be to mount them on the side of the tank, but, I'm concerned that wont
distribute the heat evenly in the tank and would be concentrated on that one side where they were mounted

anyone ever installed these pads on tanks that are resting on the frame/belly?