Well, now that Spring is here I thought I would let you know how it performed. Generally, I am quite pleased with it. there are a few things I might have done a bit differently. Mainly, I found that lifting the tub in and out was a pain because the power cord is wrapped with steel spring-wire to prevent horses from chewing on it. This is a good thing, but it always catches on everything when I pull the tub out of the box. Fortunately, I had the forethought to put handles on the outside of the box so I mostly just drag the whole thing around when I clean it every day and it is no big deal. If I make another, I might make one side of the box drop open on hinges. Although, that would make the whole thing more complicated to build. Since I can manhandle the thing pretty easily and it works as is, it is not likely to make it onto my to-do list anytime soon.
The only other issue I had with it is that, once Gabe got here, it was a bit too small and I had to fill it twice a day. Since I have a hydrant right in the barn, this was also no big deal. If I had to use a hose that then had to be drained after every use, this would have been a big problem. This tub will be perfect for the donkeys if I keep them separated from the horses next year, but will not be adequate for everybody. Since I only had Emma and Tessa in mind when I made the box, it is not really a fault in the design. It was my faulty wishful thinking that created that little problem. I hadn't been planning on having a third equine when it was built. Foolish me. If you only have a couple of animals to keep hydrated, this is an excellent choice.
As for it's main function of keeping the water from freezing at a very low cost, it worked great. The water never froze even once this winter and, by my calculations, it cost me less than $1 a month to operate in spite of never getting around to finding a lid for it as I had planned. I had it plugged into a timer so there was only power going to it for about 3 hours a day. This, combined with it's own internal thermostat, meant that it ran for no more then a few minutes every few hours. The horse's water consumption never went down and based on how much water I put into it each day, I would say that Tessa and Gabe each drank about 10-12 gallons a day and Emma, 3-4 gallons. This is right where they should be and since inadequate water consumption is one of the main causes of colic in winter, this gave me a lot of peace of mind.
Overall, I am very pleased with how this little project worked out. If any of you battle with frozen water in the winter, you may want to try something like this. Even if you don't have electricity available, the super insulation will help keep the water from freezing hard. There were many days this winter when it was not plugged in at all. I found that it only needed to be plugged in when the temps dropped below 20 degrees. It was easy and cheap to build and passed inspection without trouble and very little bribery.
