Any one know about a solar powered water heater for water Tubs. I know about deicers and Heated water buckets but would be nice to have a solar powered one .

I assume you are talking about watering your horse in the corral or pasture.

I use a Bar Bar A horse drinker. It's not solar, but uses heat from the ground to prevent freezing in the winter. The water line and valve are 48-60 inches below ground. So below the frost line. When the horse press on the paddle, water flows up into the bowl. It works great.

Google "Bar Bar A Horse Drinker"