Bring the Chlorine up to shock level and keep it there by adding more as the level drops, you need to maintain shock level until it stops dropping and until it holds for at least 24 hours, the longer the better. The point is to maintain the high level so you will need to check it every hour or so and adjust. As far as using the 6 way shock, it probably has CYA in it and your level is already on the higher side, to much higher will cause more problems, best to stick with Liq. Chlorine.