Thanks.  Simply amazing what we pass around the world with this plastic box. I new there was lots of cattle in that photo. Never dreamed of watering 600 head out of 6 little holes.  Understand cattle drink different in winter than summer and the available water needs are different.  You might not understand what I said. Think about the opposite of your photo.  600 head and it is 100 degrees in the sun. I have seen some designs that lift with loaders over tanks to cover them in the winter doing much of what you are.  Take care, speak up if you ever come south will let you check our tire tanks for two legged animals.