I was skeptical. It gets really cold here! This has been around for a very long time. I don’t know why I didn’t try it earlier!
The closer the temperature is to 32°F the longer the water stays open of course, but this makes a big difference as low as 0°F. My ducks and chickens get their water in a Fortex pan in the pen and a small Fortex bowl in the hen house. I doubt this would work well in the solid plastic water with a white top and red bottom that I use in the warmer months.
Fill a 20 ounce drink bottle with 1/4 cup of salt and hot water. Place the bottle in the water pan. It won’t keep the water from freezing but it will keep it accessible longer. It took two days for the birds to figure out that if they pecked at the open water around the bottle they could get to more. The water in the bottle never freezes but the water in the pan does eventually freeze solid on the coldest days.
I have two sets of bottles. One set is always in the pans. When it’s very cold I bring the second set in and warm them in the pot of water kept on the wood stove for moisture. The water pans are very cold so I take hot water. By the time it’s poured into the cold pans and the birds are let out it’s cooled down to warm. Instead of making three or four trips a day to the hen house and pen I’m making only two, morning and evening. Animals need to be well hydrated to stay warm most efficiently.
A few people have asked if I’m making the birds less hardy by giving them warm water. I don’t believe so. They’re surviving -25°F nights so they’re certainly hardy. I do believe I’m making those long nights easier by keeping them well hydrated and healthy.