The water thing is frustrating. I finally attached a float to the side of a large plastic tub for the goats water. That way it is always full no matter how much they drink. It is harder to know how much they drink, but it is a sure way to keep them from running out. Especially where it is very hot.
The large plastic tubs are about $9-10 and the floats come in different sizes, the one that fits the tub is about $9.00 for plastic $14 for metal. So far so good it seems to be working well.
(For horses they have larger ones for the tanks)
Yep the plastic tubs can work if they aren't deep enough for a kid to drown in. I use the horse waters that have the little bowl, and two of the small metal wash tubs, with the clamp on float. Of all the automatic waters I have tried, I like the dog version that is a flat 4" deep version with a hose attached, you just hook it to your garden hose and tada, you're done, and the babies can't drown.