Cleaning water and tanks

  • Clean your water tank often throughout the year to prevent algae growth and unclean conditions.

  • Always use bleach in the recommended amounts and follow the respective wait time.

  • Don’t use scented bleach products.

  • Adding bleach to relatively clean water and allowing wait time is an effective way to disinfect your water tank

Horse drinking
Keeping your horse’s water and tank clean encourages drinking and helps keep your horse healthy.

Cleaning your water tank

  1. Empty the tank.

  2. Scrub it clean.

  3. Rinse the tank with a 10 percent bleach solution.

  4. Rinse it twice more with water.

  5. Refill the tank. The horses can safely drink from it right away.

Adding bleach to your water tank

You can add bleach to existing water in a tank. You can effectively disinfect water tanks by using household bleach in recommended quantities. After adding bleach, wait at least an hour before letting your horses drink from it. This will allow the chlorine time to dissipate. If the water is less than 50 F, you should increase the waiting period to two hours.

If you want to treat water from a lake, stream or shallow well, double the amount of bleach you use and wait 2 hours before letting your horse drink. These water sources likely contain chlorine resistant parasites from animal droppings.

Always adhere to the recommended bleach levels and the subsequent wait time to prevent over application, which can lead to toxicity. The table below outlines how much bleach to add to certain amounts of water to disinfect relatively clean water. Always use unscented bleach products.

Gallons of water to disinfect Amount of bleach needed*
1 2 drops
5 11 drops
50 1 3/4 tsp.
100 3 1/2 tsp.
500 6 Tbs.

*Will produce water with about 2 parts per million of chlorine.

How often should you clean your water tank?

You should clean your water tank often, even in the winter, to avoid algae growth and unclean conditions. Algae growth may cause your horse to drink less and can be toxic in some cases.

Marcia Hathaway, professor of animal science, College of Food, Agriculture and Natural Resource Sciences

Reviewed in 2018

Share this page:

© 2018 Regents of the University of Minnesota. All rights reserved. The University of Minnesota is an equal opportunity educator and employer.