Potash
Add more chlorine
add a PH reducer chemical
Reduces alkalinity of swimming pool water (softens hard water)
It is necessary because the chlorine kills all of the germs that enter the swimming pool.
Usually you would add muriatic acid to adjust the pools acid level.
water seems likely to lower tha levels?>
Yes you can add shock solution to your swimming pool after or at the same time as a clarifyer. You should not swim in your pool for at 4 hours after shocking it.
You can swim usually 24-36 hours after you add the liquid.
Most likely not.
Add rain water this has very low alkalinity
Yes, you can add a clear saltwater system to a ProSeries 14' X 42" Metal Frame Swimming Pool.
You shouldn't add chemicals to a pool in which people are swimming. Add the chemicals, ensure that you've made the correct adjustment to the water chemistry and that the water is safe, and then allow people back in. To be honest, it probably wouldn't hurt them - but it wouldn't be wise.