Homemade Bottom Heat Supply

[DennisinPa]

Hello everyone,I had a store bought heating mat fail after only two seasons sooooo I built my own

The box is 29"x16"x11 1/2" high,it is painted white on the inside bottom and sides and the inside bottom of the top is painted black.

There are two light fixtures inside with low profile 40 watt flood light bulbs controlled by a dimmer switch.

I use a remote food test thermometer inside the plant tray to monitor the soil temp.