**Sani-Marc Anti-Chlor Knock Out, 1L - 30-10110-11

If you wish to decrease the sanitizer residual rapidly, use Knock Out and take advantage of your pool immediately. Knock Out will not affect the colouring of vinyl, cement or fibreglass pools.

When you start your pool, at springtime or during the regular season, shock treatments are required and a waiting period is necessary until the residual value has dropped to the recommended levels of 1 to 3 ppm.