Laguna Barley Straw helps maintain superior pond water conditions in a completely natural way. The barley straw comes in small slow-release pellet form for easy handling and convenience. Simply place the pellets in a mesh bag (included) and immerse in the water. Over the next several weeks, the pellets will release an enzyme that helps promote clean and healthy pond water. Laguna Barley Straw is completely natural and will not harm fish or plant life.