Finally got my temperature controller wired up. It isn’t easy when you have to be thrifty but I think I did well. I got an aquarium temperature controller from ebay and some random parts and put it together for 1/3 the cost of buying one. This controller has two outputs, one will go to the free chest freezer we got from Craigslist, the other will go to an aquarium heater in a water bath the carboy will sit in. Once I set my temperature, the unit will decide if the heater or freezer needs to be on and then will turn off whichever once the desired temperature is met.