1) how long does it usually take for one horse to empty an average-sized stock tank?
Depends on how big the stock tank is. My current horse drinks very little. I think she drinks maybe, maximum, 5 gallons a day. My previous horse drank like crazy -- probably twice that much.
) does anyone use nets on their roundbales, and if so, what kind do you use? (I'd like to save money and make my own)
I didn't. For one horse a round bale is a pain. More waste than anything. Even for two, I used to peel off rounds for them daily rather than put the bale out. My girlfriend used one of those bale buddies and it save a lot of waste, but she had three small horses at the time.
do ya'll move your roundbales without a tractor? I have a big truck, if that helps.
I would just roll it to where I wanted it. At one time, I would push it with the bumper on my Chevy, but it was an old Chevy. Did a number on my bumper!
how long does a roundbale usually last for one horse in winter, with and without a net.
Bales come in such a variety of sizes we can't tell you that. Plus, it depends if it's soft core or hard core so you have to go by the weight of the bale. I would guestimate anywhere from 15 days to a month...