Put an end to the hassle of dumping and scrubbing out slimy green water tanks. 100% organic barley straw helps keep stock tanks clean and drinking water palatable for up to two months. When barley straw is added to water, it begins to decay. This decaying process releases lignin, which then interacts with algae and causes it to die. Completely safe and effective treatment contains no chemicals, pesticides or herbicides; no toxic side effects. Can be used with cattle, goats, sheep, swine, all breeds of horses, poultry, fish and even exotic animals. Also great for automatic waterers, bird baths, ornamental ponds and fountains. Easy to use, just place one unopened burlap bag in the tank. One bag is good for an average 200-gallon stock tank. For larger or extremely dirty tanks, use two bags. Begins working immediately but may take 7-10 days to notice its effects. Scoop out any floating debris. Replace every two months. Burlap bag is completely biodegradable.