Curious - 1/10/2024 15:49
We had the red one with the sloped hopper in a large redwood tank.
I actually enjoyed keeping it going with cobs and wood scraps.
I also remember all of the plumes of smoke from tank heaters on a still day when you looked over the countryside.
Dad believed it was much better for the milk cows to drink the warm water than the cold water from the automatics that followed. He said the tank heater never drafted properly after he built a silo nearby.
I've wondered how many more calories a cow has to burn drinking cold water than warm. Has to drop there body temp somewhat not sure if you would see a difference in fodder consumption or body condition though... | 
Poor man’s tank heater part 2
