MCGRAYEL COMPANY INC 64 OZ ALGATEC Will not interfere with pool water pH, or sanitizer levels and can swim immediately after treatment Kills rather than starves algae and prevents algae regrowth due to biostatic inhibitors Kills most algae in 8 to 24 hours; black algae in 7 to 10 days Salt pool friendly Formula contains no metals, bromides, or quats; Works synergistically with chlorine for fast cleanup Super-clarifics pool water during cleanup function