An easy solution would be to go get a Lutron Credenza lamp dimmer(plug and play already) from Home Depot or Lowe's and plug a second piece of flexwatt into it, and then plug that into your thermostat. Dial the dimmer down about 3/4-1/2 way down and see where 83-84 degrees is and once it is there, tape the dimmer so it doesn't get moved. Once it is set, the thermostat will take care of the rest. It sounds weird, but it works perfectly. I am using the same method on my 8-shelf rack for the cool side flexwatt. Dimmer plugged into Helix, and flexwatt plugged into dimmer. It keeps the cool side at 84 and the warm side at 95. Works great and is a more inexpensive alternative if you're in a bind.