Fashioned into an attractive, floating showcase for non-submerged aquatic plants, these barley planters are safe for fish and other pets and wildlife, and provide the water clarification benefits of our barley straw bales. Small planter measures 3.5-inch by 6-inch and treats up to 500 gallons. Hidden styrofoam ring for stability and floatation. Keep your pond water clean and clear year-round. Clear-Water Barley Straw Clarifiers are easy to use, safe and attractive. Clear your pond, fountain and fish tank naturally. Acts as a natural filter to keep your pond clean and clear. Won’t harm fish or plants. Works up to 6 months.