I made a watering system this summer from a 5-gallon bucket and a 5-gallon water cooler jug. Drilled holes in the neck, cut 4 larger round holes 2" up from the bottom of the bucket, evenly spaced. Turn the water cooler jug upside down in the bucket. Works awesome. Except when it freezes. Which is now. I need to find an element I can stick in there. Low wattage, just enough to keep it from freezing. I've looked online, but maybe I'm not typing the right keywords. I checked my local TSC too but I don't see anything there. Any ideas?