Water is one of the five recognized requirements for life. During the summer heat a resting horse will consume about 10-15 gallons of water per day. In the winter this figure drops to 5-8 gal/day.The water should be clean and fresh to encourage adequate consumption. The cleanliness, freshness and temperature of the water affects the amount a horse will drink. Dehydration and heat stress are the top reason for colic in Southern Arizona during the summer month.
Each barn or stable is unique in its presentation of water for the horse. Having a large water tank in a pen with a single horse may not be optimal. It would be easier to have a smaller tank that could be cleaned on a regular basis. If your horse is going to drink 15 gallons of water in a day why present him with 100 gallons?
Some like the muck basket on the left which get cleaned daily and filled nightly. The result is fresh clean water offered on a daily basis. The added bonus is the ability to monitor water consumption over a 24 hour period. This is an example of good horse husbandry. Some use 50 gallon tanks and clean and refill them every few days. A pool net can be used to clean bits of hay and debris. Automatic waters are a neat and tidy source of fresh water but do require daily checks and weekly clean outs to prevent algae and bird dropping accumulation. The down side of automatic watering systems in the lack of ability to monitor intake by the horse.
Goldfish or Koi have been used to eat algae and mosquito larvae in larger tanks. If you are only watering a few horses why not use an appropriate sized tank that can be cleaned before it looks like the one on the right?Which water would be more palatable to the horse?Horses have to consume adequate water to stay hydrated. A dehydrated horse can be more prone to heat stress, colic from impaction and electrolyte imbalance which can lead to poor performance and kidney stress.I had a riding instructor in my youth who summed up stable management succinctly. “Honey, if it is worth doing, it is worth doing right.” I agree.