Clear Water Barley straw is the natural alternative to treating decorative cloudy water in garden and fish ponds. Specially designed for economy and ease of use, each Bale lasts six months and includes a cork float. Transparent mesh Holds together without the need for barley detracts from the pond fish and plants. Slip bales under the plant environment Walk part of the existing pond. Treats 2,000 liters of pond water. It will not harm fish or plants. year treatment for a low price.