Studies have shown that barley straw is an effective means of controlling algae including string algae. The beauty of using barley straw is that it is ecofriendly. Studies have shown that the chemicals released have no negative effect on higher plants and that it poses no harm to fish or invertebrates in a pond. 8 ozs. of Premier Ponds Barley Staw Bale treats up to 1000 gallons for about 3 to 4 months. PremierBarleySize: 8oz. Barley Straw-Treats 1000 Gallons1lb. Barley Straw-Treats 2000 Gallons (+$14.00)2lb. Barley Straw-Treats 4000 Gallons (+$24.00) Most Orders Shipped Out Same Day! Premier Ponds LLC pondinfo@premierponds.com U.S.A. Copyright © 1999 - 2007 Premier Ponds LLC, North Salem, New York. All rights reserved. Thermo-Pond Heater 3.0, Aquascape Designs Pond Kits, ScareCrow Sprinkler, Nursery Pro Micro Pond Kits, AquaClearer, Microbe-Lift, Great Blue Heron Decoy, Pond Liners, Thermo Pond Heater & Deicer, Premium Koi Food, Select Koi, Butterfly Koi, Pond Aeration Pumps, Flexible PVC Piping, BioFalls, Skimmer, Aquascape Pumps, Cat Stop!, Animal Control Products, Pond Netting.