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Last night, I did my weekly shock with about 3 to 4 teaspoons of dichlor. Less than an hour later, I found my roommate and a friend in the hot tub before I could warn them that I had just shocked it. Usually, I wait about a day. I guess nobody dissolved in the water, because everything seemed in order when I left for work this morning. I had about 5 PPM FAC at noon today. I told them I thought they would probably be okay, but might experience dry, itchy skin. This is the first time I've encountered this situation and wondered just how harmful it is to get in water right after shocking.
If I had a nickle for every time I checked my chlorine and it was zero, I could retire. No skin problems, cloudy water, scum, algea, bad odor. Maybe I'm just lucky.
Jumping in soon after shocking makes doing that somewhat worthless. You want to shock, leave the cover open and run the jet for 15-20 minutes. Shocking is taking your chlorine to higher levels but jumping in soon after will negate that. there's no point in shocking the spa if you know you're going to be using it soon after.If the chlorine is low or zero, add some to bump it up for safe bathing (1-3ppm) and shock AFTER use! Steve