Thanks, good to know it's safe to swim in. I just hit up PoolMath, and came up with it requiring 171 oz of hydrogen peroxide to drop from 8.5 ppm to my target of 3 ppm (I set my size to 15,000 gallons, punched in 3 as now and 8.5 as target and it says 171 oz of 6% bleach). That's a lot - did I...