Stop Hair Algae 6oz. Chem-Marin. Stop Hair Algae with our Applicator (sold sep) to any surface that contains green hair algae. For best results turn off all circulating pumps or redirect water flow away from treated areas. Do not apply directly to soft or hard corals. Do not apply more then 3 ounces of this product per 30 gallons of water in a 24 hour period. This product is reef safe and biodegradable.