>>I was reading that a trough for cows would be a good waterer in winter ...they are available with a floating top which the animals push down when getting a drink--the floating top discourages freezing <<
I have a friend down the road who uses a bottom heater in her 200 gallon tank and in the winter she uses duct tape to strap on a piece of 4" foam insulation(cut to shape) over 3/4 of the top...seems to work well against freezing. I use a 17 gallon all in one unit in the winter bc I only have 2 horses and I fill it twice a day from the hose. It has never frozen and only uses 250 watts/hour, so its very economical compared to the big ones that use 1000-2500 watts/hour. The floating top sounds like it would really slow freezing down: you could put in a bottom heater that was set to come on for an hour every 6 hours, then it would definately not freeze. Winter water is definately a challenge to prepare for! A
