Dealing with frozen water is one of the biggest challenges chicken keepers in cold climates face. I've tried most everything to keep my chickens in fresh water in winter.
 
At first, I tried stock tanks. Too expensive. Those tank heaters draw a lot of amps.
 
Then I simply hauled the water jugs indoors every night and lugged them all back out each morning. But there were days when the water froze within a hour, and I had to replace it. Waaaay too much effort.
 
The next thing I did was to assemble some cookie tin light bulb heaters. They worked fine, but they weren't up to the job of keeping water liquid all night long.
 
Finally, I found the nearly perfect solution, and they also work splendidly year round. I bought some Bright Tap nipple watering systems that screw right into the spigot holes of 5 gallon Igloo water coolers. These keep water cool in summer and help keep it from freezing in winter. If your winters are as cold as mine, you will want to further insulate the tanks by wrapping a blanket of insulation around it. I slip a wool blanket bag over the insulation to keep the chickens from tearing up the fiberglass insulation. This has served me well, keeping the water from freezing even down to ten below zero F.
 
The nipples will freeze when it gets extremely cold, so I bought a tiny nine inch by nine inch heating pad and secured it over the reservoir of the Bright Tap to keep the water there from freezing. But even still, occasionally I need to thaw out the nipples by dipping them into a small bowl of hot water. Once the chicken begin to drink, they remain unfrozen all day.
 
So, select the method that fits your needs. You will come up with something with a little imagination.