chong

Also, for temperature control of heat mats, I use a remote bulb thermostat placed inside the middle tray (I have a 5 tray mat from Hydrofarm). I bought the t'stat from WW Grainger. I work in the HVAC industry and I pay the lowest wholesale prices for HVAC equipment with them. If you have friends who are HVAC techs or engineers, you can ask them to buy them for you.

I usually set the temps at 90degF. To fluctuate the temperature, I jus open the dome to the tray that needs the lower temps for the number of hours it needs to be lower.