i have a zilla heat pad, a hydrofarm thermostat and were using a tub.The problem im having is the thermostat probe is greating a huge air pocket right around the probe,and to top it off from trying diff ways to keep it stuck to the bottom including taping the mat to the bottom of the tub with foil tape it wont stick and heats maybe a half dollar size .Any advice is appreciated we took the mat off and are using a heat pad for people we had laying around which is working for now but no what we want since it goes off after 2 hrs.