All the benefits of barley straw without the mess! Barley extract utilizes all the good properties of barley straw in liquid form. Barley Extract is designed to eliminate sludge and slime from the bottom and edges of your pond throughout the year. Barley Extract goes to work on contact and you don't have to wait for the barley bales to decompose in your pond. 8 oz treats up to 800 gallons for 3 months.