Microbe-Lift Barley Straw Pellets + balances, matures and clarifies pond water chemistry with 100% natural ingredients, while buffering the pH. This product releases decomposition by-products instantaneously which disperses evenly in the water, and then reacts photochemically with sunlight. This triggers humic acids which generate hydrogen peroxide that chelates metals like copper or arsenic and help clean the water. This product will work throughout the year, and may leave a residual at the bottom of your pond; which may easily be removed with Microbe-Lift Sludge Away. These pellets do not contain any food value, and are not appetizing to your fish.