If you have ground for your coop floor or in your run you can use this method to prevent water from freezing without the use of electricity.
Use a bucket that is appropriately sized for your flock although a bigger bucket retains heat better than a small bucket. I use either a 3 or 5 gallon...
I built my guinea coop as an 8'x12' with 8' walls. The ceiling joists are open so the guineas use them as their roosts.
Guinea coop is on left.
I have 13 adult guineas in an 8'x12' coop and it is cramped quarters for them.
In the heat of the summer the walk in door is propped open during...