GreenClean Pro Granular Algaecide Eliminate a broad spectrum of algae on contact with this non-copper-based algaecide. Designed for lakes, ponds and other large bodies of water as well as for unpainted surfaces, such as beaches, docks and walkways. Its active ingredient, sodium carbonate peroxyhydrate, creates a powerful oxidation reaction that destroys algal cell membranes and chlorophyll, providing immediate control of algae. Fast-acting (within 60 sec of application), it biodegrades completely and adds 13% bio-available oxygen to the water. Can be applied for spot or perimeter treatment. For spot treatments apply at a rate of 20 50 lbs/acre-foot; for algae blooms apply at a rate of 9 30 lbs/acre-foot; for filamentous algae blooms treat at a rate of 50 90 lbs/acre-foot. Safe for use with koi and trout. EPA-approved. Now sold in 50-lb bags.