About that water temp - Generally, my dogs would lose weight in the summer, and I noticed they would not finish their food. I had chalked that up to hunting and the heat. One year I got to noticing, my dogs drinking so much water out of the mud holes, they could not stay in a race. At first, I thought it was the water hose, that connected the header for the waterers and the faucet, giving the water a bad taste. So, I replaced the water hose with PVC, and the same thing happen. When I started checking the waterers for flow, I realized the water was really hot. I used old trampoline mats and shade clothes for a while, but they only hold up so long. I finally built a roof over the kennels a few months ago.... like I had originally planned to do 10 years ago.
I changed out my old blue barrels for some food grade 58 gallon barrels. They hold hay and shaving really well because of their shape. I found them on the Facebook Market place for $25.
https://www.amazon.com/Military-Surplus-Waterproof-Gallon-Barrel/dp/B0CCGDHY6R