Ive used those store bought zoomed UTH's under a plastic tub before with no problems. In fact that's what I used for years before moving to all racks.

What I did was use A/C duct foil tape and taped the uth straight down to the tub. Those zoomed thermostats are junk, thats what I'd replace first. With a good thermostat those UTH's should be fine on the plastic tubs.


Sent from my iPhone using Tapatalk