Two horses. Filling the bucket wouldn’t be a problem, obviously nice to not have to but that would be ok. Bucket would be under roof and stock tank would be along the side of a run in.
Definitely the stock tank. For 2 horses, one of the 70-gallon Rubbermaid tanks that take a plug heater in the bottom would be a nice choice. Assuming you’re at work most of the day and they have plenty of hay, they’re going to need upwards of 10 gallons of water apiece so a bucket is insufficient. Better to KNOW they have water than ~wonder~ if they have water! 
Stock tack for sure. Any one of my horses goes through close to 10 gallons a day each. One 5 gallon bucket shared between two would be insufficient.
Consider the cost to run the power, though. Stock tank heaters are usually 1500 watt. If you live in an area with high electricity costs, that will add up fast. As in, $125 or more per month to run it (assuming it’s on 24/7). A 16-gal 200-watt heated tub costs about $50, and 200 watts would cost you ~$35/month in electricity. The monthly energy savings would more than justify that purchase.
You don’t need to run them in the daytime unless you live in the Arctic. :winkgrin:
[QUOTE=Lady Eboshi;7871079]
You don’t need to run them in the daytime unless you live in the Arctic. :winkgrin:[/QUOTE]
Or in a very large chunk of the US…pretty much including the entire Midwest… 
As for the OP, a heated muck bucket might be a nice compromise. At the barn I board at they use a trough and heater, but there’s usually at least 6+ horses out there at any given time.
I like the heated buckets because they draw less electricity than the trough heaters. Years ago, we had extreme cold and my trough heater overloaded my barn electric and threw the circuit breaker. The water froze and 1 horse coliced. Now, I use electric buckets, either several 5 gallon or two 16 gallon. I always like to have redundancy in case one bucket fails.
I should add- there’s a running creek through their paddock too so this is just to make sure there’s warmish water available. We’re in central Pa.
If cost to run is a factor I would recommend the stock tank heater over the buckets. One year I tried using several heated 5 gallon buckets instead of a larger tank. My bill was more. Plus I had to fill them up over and over. Tank is definitely better.
I utilized stock tank deicers for many years when I had my farm in Tennessee, as it was the most reliable way to provide multiple horses with water in the winter (they lived out most of the time with a nice run-in). First of all, I NEVER saw my electric bill go up $100+, and we experienced some cold winter with extended freezes. Honestly, I’m not sure I noticed much of a difference in the electric bill. However, the extra $$ would have been worth to to be sure that my horses had access to deiced water 24/7.
Tank deicers don’t run constantly and they don’t actually “heat” the water. They operate on a thermostat to keep the water temperature above freezing, turning off and on as needed to prevent icing. So they really aren’t that expensive to run.
I had a 100 gallon Rubbermaid trough and my preference was the drain plug deicers. No cords going over the top of the trough to invite chewing, and the horses aren’t tempted to play with them like the floating ones.
Maybe my electricity is cheap. Maybe 10 bucks more a month and that is NEVER unplugging. But it’s so hard to figure with chicken coop lights and fount heaters, furnaces, plugging vehicles in etc.
I prefer a heated muck bucket shared by my big horse and mini in the winter over the heated 50 gallon stock tank. I figure I’m saving money because I’m not keeping more water than they drink in a day ice free.
[QUOTE=HungarianHippo;7871071]
Consider the cost to run the power, though. Stock tank heaters are usually 1500 watt. If you live in an area with high electricity costs, that will add up fast. As in, $125 or more per month to run it (assuming it’s on 24/7). A 16-gal 200-watt heated tub costs about $50, and 200 watts would cost you ~$35/month in electricity. The monthly energy savings would more than justify that purchase.[/QUOTE]
Excuse, but K & H makes 250 watt, on up, size stock tank heaters. So your cost paranoid example, is just that. Paranoid. The K & H heaters have thermostats, so they turn on & off as needed. Applause to them for that. Another HUGE savings factor on electricity, bedside using being smart enough to use a smaller wattage heater in the first place…
I cut a piece of plywood to fit over slightly more than just half of my 100 gallon Rubbermade stocks tanks. Cut a sized to fit hole in the plywood, where the heater cord WITH ITS COVER, come out of the top of the stock tank. I cut this hole so the cord will then be hidden behind the tank & unreachable to prying paws & nosey mouths. Then bolt the plywood cover onto the tank.
Not only does it help hold in heat during the winter, especially during the strong Prairie winds we get here in Oklahoma; in the summer the cover helps to shade the water from the sun, keeping it significantly cooler.
I painted my plywood black side up for winter. White side up for summer. I went the extra mile & then coated the paint with a food grade varathane or urathane I bought on Amazon. So any snow melt or rainwater that runs into the tank is not tainted from paint. I know, a little paranoid, but I love my for legged beasties. 
Another thing I do for the water tank is set in the slightest depression of earth, that I filled with fresh manure. I then bank the water tank with compost for added insulation. When I do change the tank water, I try to dump so the water goes into the depression, thus preventing an ice slick around the tank. Then rebank the compost.
Quite honestly, I have never had an issue using just the 250 watt heater. The top cover makes all the difference in the world. I do own a 500 watt heater, just in case. but have never had to use it. Granted, I do not live in Buffalo NY with 8’ of snow.
Here is their zone chart: http://www.khmfg.com/edi/images/media/Instructions/Stock-Tank-Chart.pdf
They say I should be using a 500 & 750 watt heaters on my tanks, but again, putting a top cover on the tanks makes all the difference in the world! We do just great in subzero weather with the 250 watt heaters.
One can also build an entire plywood box for their tank, & insulate it if they choose. Thus making a small wattage tank heater more probable for those in the perpetually frozen Great White North. Though again, covering at least a portion of the top of the tank makes all the difference in the world. Me, as said, I just bank the tank with compost.
If one has an appropriate plug in place, they may also try using “Thermo Cube” type plug ins, to help save on electricity. I have seen them for sale in a couple of different on/off temperature ranges. http://www.amazon.com/Farm-Innovators-TC-3-Thermostatically-Controlled/dp/B0006U2HD2
Hope what I do saves others many dollars. It sure has saved me $$$.
or use a timer.
[QUOTE=flypony74;7871267]
I utilized stock tank deicers for many years when I had my farm in Tennessee, as it was the most reliable way to provide multiple horses with water in the winter (they lived out most of the time with a nice run-in). First of all, I NEVER saw my electric bill go up $100+, and we experienced some cold winter with extended freezes. Honestly, I’m not sure I noticed much of a difference in the electric bill. However, the extra $$ would have been worth to to be sure that my horses had access to deiced water 24/7.
Tank deicers don’t run constantly and they don’t actually “heat” the water. They operate on a thermostat to keep the water temperature above freezing, turning off and on as needed to prevent icing. So they really aren’t that expensive to run.
I had a 100 gallon Rubbermaid trough and my preference was the drain plug deicers. No cords going over the top of the trough to invite chewing, and the horses aren’t tempted to play with them like the floating ones.[/QUOTE]
I guarantee that in Tennessee, your cold winter with extended freezes is not the same as northern Midwest winter. So it’s all relative. Cost of electricity also varies wildly among regions.
PS: Raising the temperature of water to keep it from freezing is heating it. And tank heaters do run constantly when temps are well below freezing, even mid-day. Which they are, for months at a time here. Count yourself lucky that it doesn’t take much energy to keep your tanks from freezing over, but don’t assume your reality applies everywhere.
I’ve been running two 100 gallon Rubbermaid heaters with plug deicers in them for years, and have never seen my electric bill jump more than $50 per month. I’ve done it on two different farms- one in the Poconos and the other in Central PA.
Heated buckets make me nervous because they can be drained by two horses very quickly and they seem to be a HUGE cause of barn fires. Our heated stock tanks are all outside and the plug in deicers we use do shut off when the water level gets too low.
Electric is priced like gold here but that said…
I still bought a heated bucket for the Donk’s stall. I have a stock tank in my barn with a plug heater and a heated muck bucket for when I have him out of his stall. I also have the insulated buckets in the stalls, which froze solid the first day I installed them 
So far no circuits blown. Colic is more expensive that power.
I use the heated 16 gal muck bucket for two of mine. I’ve been using the same one for about 3-4 years. Works great and is easy to dump and clean. I top it off in the morning and evening and have had no problems with running out of water. It does have a thermostat and will shutoff to avoid overheating. More economical then stock tanks because you don’t have to heat up as much water.
http://www.tractorsupply.com/en/store/allied-precision-heated-bucket-16-gal?cm_vc=-10005
I vote for the tank with a heater. I wrapped my tank with 2" thick upholstery foam that I slid into waterproof contractor bags to insulate the tank. We were able to unplug the heaters during the day as long as the temps were in the 20’s. Below that and we kept it plugged in all the time. But the heater does cycle on and off, it’s not running continuously. I also floated a piece of hard foam insulation on the surface, but smaller than the surface. Not only did it help to keep the water warm, but its movement helped to prevent ice from forming.
I like the reassurance of knowing that I have a substantial amount of water on hand all the time. Last winter we had a water main break & no water source for 5 days. We were able to bring in some buckets, but we were also able to add clean snow to our big tank and had plenty of water available.
