This may or may not be helpful because, like anything, what works for me may not work for you. I think because I am able to check on them at lunchtime (or sometimes more often) due to current work-from-home situation, I feel ok with my set up. It has been on my list to try insulating my muck buckets this year. Unfortunately, haven’t done so yet.
Crazy as some may find this, my latest setup for the last couple years is just unheated muck buckets. I have only a couple horses per pasture now and this works for me and them. I live in northeast, temps can go -20F at night and not go above freezing in day. They are out in day and in at night. I use blue muck buckets. Light blue in summer and dark blue in winter. I found the bucket color does make a difference, dark color heats up better in winter sun and light blue is less prone to algae in summer. It’s not a fantastic difference, but I like to observe and take mental notes of what works. Bucket placement also matters. In one section of the farm, have 3 pastures that come together in one area and all buckets for those pastures are co-located for easy filling/cleaning/checking, they are within 50 feet of each other and each freezes over at different rates purely because of location. One other bucket that is located up against a south-western facing dark colored cement block building and blocked from northern wind rarely freezes. I top buckets off at night or cover them and most often can just remove a varying layer of thickness disc of ice in the am, then top if off with fresh water and that usually keeps for the day. I keep spare buckets handy so if we are in a cold snap or ice has built up along insides, I can turn a frozen bucket over in place, fill a spare bucket next to it, and later that day with gravity/sun, the bucket releases from the ice and pops off easily – much better than breaking ice and breaking buckets. Also, these buckets are on a large gravel pad and can take the dumped water/melting ice without causing mud. It does help to put something between bucket and ground – wood or something with a piece of insulation. I have one bucket of those three that will freeze faster than the other two as it is more exposed to the wind, so if you can avoid wind, that helps too. I will sometimes put out a second muck bucket or pull out the 100-gallon tank if I’m worried about a cold snap or I will need to be away longer than usual. Like I said, I only have a couple horses per pasture now and they don’t play with water, so this works for the crew I have now.
That said, I have tried other methods and with varying numbers of horses. I have on hand, and have used, heated water tanks – both the muck bucket ones with heater elements on bottom (which use noticeably less electric according to my electric bill) and the submersible heating elements that I used in 100-gallon tanks. I did not have electric wired to the pastures and used extension cords (which are not recommended). I wanted to figure out where to run buried electric lines and played with different layouts, buried electric is still on to-do list unfortunately. I ran all cords through metal pipes up to the heaters. The pipes had to be big enough to get the plug through. I found the horses did not mind walking over the pipes on way to and from barn (pipes were NOT in pasture) but no matter how carefully I tried to put the pipes out of the walkways, it seemed the people would complain about them being a trip hazard or having to get the muck bucket cart over the pipe, etc. The pipes just didn’t work nicely for the setup here, it seemed clunky, and I always worried about them. Something buried would obviously be better. But better than no heat? Horses need heated water, right? Ah. I had read that is not true, is this possible? I also know several barns in my area don’t have heated water and the horses seem to be doing fine. So, I set up cameras. I put heated water next to unheated water and watched. For several winters. The horses here drank from the unheated water more often. I filled the heated tanks more due to evaporation, but the horses actually drank more from the unheated buckets. This may or may not be the same for your horses. I had more horses here then and the results were the same over several different pastures of varying number of horses over several years.
I had one horse that always played with the submersed heating elements. No matter how I tried to brace it to the bottom or pipe the cord, this horse just thought it was a toy to disassemble. This horse would also put his feet in to try to dislodge it. That’s when I switched to the smaller muck bucket size with the heating element safely on the external bottom of the bucket.
I tried the manure pile bucket (pack compost around 100-gallon tank). It does work but I had a horse that liked to dig. Compost is really good digging. Only did that one winter.
I had a horse that was a swimmer. All four feet in a 100-gallon tank numerous times a day, summer or winter. I didn’t say she was sane. For her I built a top for the 100-gallon tank. Plywood with 2x4 sides that hung over the edges to keep it on. I think it was a 26” or 28” square cut in top for access to water. This successfully stopped the endless swimming but also helped deter freezing in winter and algae growth in summer. I was never comfortable putting a heating element in her water tank, even after the cover was on.
So, that’s my experience, hope it helps. It really hasn’t been that bad the last couple years with my set up. Like I said, I planned to insulate the tanks this year and I think it could be better with some insulation around the tanks. If worse comes to worse and it stays as it’s been, it won’t be the end of the world. The horses seemed to drink healthy amounts of water outside and always have water inside at night that doesn’t freeze. I think having extra muck buckets is key though. If there’s a deep freeze, it can be hard to remove the ice on the sides, especially when in a hurry. Much easier to just fill a new bucket and it takes longer to freeze with all fresh water. Frozen muck buckets also break easily so don’t be tempted to use a sledgehammer to loosen the ice grip on the plastic! (Barn helper did that once, bucket lost)
