Put an end to dump-and-scrub of water tanks, tubs, buckets. Keep water clean and palatable for up to two months. One bag treats up to 200 gallons. The Barley straw treatment has been used for years as a water treatment for horses, cattle, goats, sheep, swine, poultry, fish and exotic animals and plants.To use, tear off label and put bag - unopened - in tank. Be sure is on bottom (Rock or Horseshoe weight).