Water

My horse doesn't seem to drink much water. I notice him going down to the water every now and then, but it seems to take forever to empty. It's a 70 gallon tank, but since it's on a slight hill, full, it's probably only about 60 gallons. It's been over a week since I filled it, and it's not empty yet, and a lot of what's gone is probably evaporated, since it has a water heater in it.
How much should he be drinking? Is it bad if he's not drinking enough, or should I just trust him to drink when he needs to?

I notice that our bunch drinks less this time of year. I think the colder weather has something to do with it. In summer they drink much more. Make sure your tank is grounded too, with the heater in it he may be getting little jolts.

Horses with generally drink somewhere around 10 gallons of water per day in the winter whereas in the summer they may drink 20-30 gallons per day. It really depends on the weather.

What do you mean by the tank being grounded?

If your heater requires it (it should say so on the directions if you still have them) you must ground the tank. If a short occurs in the cord or heater itself, grounding the tank will prevent elect. From going into the water in the tank. I use a copper wire and long guttering nail. Wrap the wire around something on the tank, I use the drain plug, and then around the nail and drive the nail into the ground. I'm not sure if that's a proper way to do it or if I should be using a ground rod but its better than nothing. I use a submersable heater so I also run the cord through a piece of PVC pipe so the horses can't pull the heater out or bite the cord.

In Australia we are almost the exact oppisite, we need to buy coolers for our horses water Horses are just like us, in winter we don't drink nearly as much as we do in summer, because of the weather. Jojo, I wouldnt worry about it to much...If he was thirsty he would drink. But yeh, get that heater checked out like Vidaloco said.

Thanks everyone. I'm feeling better about it now, I saw him go down and drink some a couple times so I know he's not just not drinking. He eats a lot of snow, which I've heard isn't good for them, but he really likes it. I dunno.

Its summer time here now (australia) and my guys all drink on average about 40L a day (10 gallons). Sounds like your guy is on track considering its colder over there now :)