Chemistry is a branch of physical science that studies the composition, structure, properties and change of matter.
Daily water consumption varies quite a bit. Season of the year, workload, reproductive status, diet, and climate factor into the volume of water needed by a particular horse on a specific day. As a starting point, the average horse drinks between 5 and 10 gallons (19 and 38 liters) of water each day. The horse may need slightly less if it is grazing lush pasture because fresh grass contains a high percentage of liquid.
Warm Weather Woes. When the weather entices your horse to drink more water, you have to be diligent about preventing stagnation. During warm weather algae grows quickly, sometimes in a matter of hours, and can become toxic. In extreme cases your horse can suffer muscle and organ damage from blue-green algae toxins.