you can try a Ultratherm Vivarium Heaters (UTH's) , they have a laminate, very low wattage usage that being said, i think they're better used on a proportional thermostat than an off and on one, with the on and off theromostat once it reaches the desired temp it will shut off and these take a little longer to heat back up ,so temps are inconsistent, being very low wattage. the company says you can use them without a thermostat and they wont over 100 deg, but PLEASE do not try that, always use thermostat even if its an of and on one.