Home brewer? Need a cheap way to control the temp of your fermentation carboy? We went to Boxer (a restaurant supply store) in Portland and bought a big tub (~1.5ftX1.5ftx2ft). Then we went to a local tropical fish shop and bought a submersable water heater (make sure it goes below 70) and a submersable pump to keep the water moving. Threw the pump & heater in the tub, poured ~10 gallons of water in, placed our carboy in the water, and our hefeweizen has been sitting happy at 70.4 degrees ever since. Total cost ~$60!