Sometimes the simplest things work best. I found my 2 pink clam shell-shaped pools on clearance at Wally World for $13. They needed to be small enough to move and dump easily when full without using so much water to fill them up. We have well water, and in dry years we have to ration water for dishes, showers and laundry. This winter will be our first winter with ducks, so the pools will not be an option when it freezes, since I don't imagine my husband will want to come up with a way to keep swimming pool water for ducks from freezing.
If anyone has an inexpensive way to keep a pool of water from freezing this winter, I'd like to hear your idea.
The worst part about having animals to take care of is that's it's impossible to be away from home overnight without finding someone to take care of everything while you're gone, and someone has to be home before dark so the coyotes don't have duck a la rouge for dinner.
I did find a suggestion to use spa or swimming pool chlorine instead of household bleach in the pool for the ducks to help keep it clean.
Thanks for the comments