We use 3 or 4 inch flexwatt with a Helix Controls DBS1000 Proportional Thermostat (Grounded) and it keeps the temps right where we want them after we set them. you can purchase from http://www.reptilebasics.com/Flexwatt-Heat-Tape-p-1-c-297.html and if you order the clip sets and leave them a message they will hook up the heat tape for you so alls you have to do is install the Helix and be up and running in no time.