Chlorine Usage Per Soak Question

[Maxemily]

I am uncertain as to chlorine usage on the per person per soak angle.

I recall the usage numbers being 7ppm of FC per person hour in 350 gallons.

Does this mean after three people soak for an hour in a 350 gal. tub that began with 1ppm FC, I will need to add the equivalent of 20 ppm of FC - 10 tsp of dichlor or 5+ cups of Clorox?

Will adding this much chlorine theoretically result in a 1ppm residual FC level the next day because it takes that much to clean up what we do to the water?

[Maxemily]

Anyone?

[chem geek]

Anyone?

Sorry. I must have missed your post when you originally posted it. If 3 people soak for an hour in a 350 gallon hot tub, then this requires about 7*3 = 21 ppm FC of chlorine or MPS equivalent. That's almost 11 teaspoons (almost 4 tablespoons) of Dichlor or 15 fluid ounces (almost 2 cups) of 6% Clorox Regular unscented bleach or 22 teaspoons (a little over 7 tablespoons) of MPS.

I'm not sure how you calculated 5 cups of bleach, but the rest of what you stated is correct.

This amount of chlorine should get used up by the next day and the residual should be very low. Remember that the above is a guideline and will depend on the temperature of your hot tub and how much you sweat. It's a rough average so you can adjust accordingly by seeing what sort of residual you do end up with the next day. I would guess that the amount is conservative at higher bather loads since some chlorine usage is independent of bather load (fixed amount per day even when not using the tub).

Richard