EasyPro EBS1 Barley Straw Bale for Ponds and Waterfalls, 1-Pound Each one pound bale treats approximately 1000 gallons of pond water A one pound bale last three - four months, apply second bale four weeks after first treatment to avoid interruption in water quality Best results if applied early season Eco Friendly, Chemical Free - All Natural Safe for fish, plants & wildlife!