Chlorine will indeed affect alkalinity. It will lower the alkalinity. If you add chlorine gas to water, it will create hypochlorous acid and hydrochloric acid. Cl2 + H2O <-> HCl + HOCl Sodium Hypochlorite (Bleach) will do the opposite and raise pH.
Low alkalinity in itself is not a problem. But it may affect your other water chemistry levels, such as chlorine. If there is not adequate free chlorine, you could have contaminates in your pool water.
The level of total dissolved solids in water does affect chlorine disinfection. That's why there is a recommended specification for the level of total dissolved solids in water for the water that is sent to homes.
Total Alkalinity acts like a buffer for your PH level in the spa, if your alkalinity is too high your pH is also probably too high. These acid levels can affect the feel of the water which can irritate the skin and the eyes. It is not harmful but should be adjusted using a chemical like PH down (sodium bi-sulfate). The real problem with Alkalinity being too high is that this can affect how well the chlorine is sanitizing the water, the higher the PH and Alkalinity the less effective the chlorine or bromine is which leads to your water not being properly sanitized. Also remember when adding PH down to lower your Alkalinity you should stay out of the hot tub for a few hows as that is a granular acic that your are adding and you want to give it time to dissolve into the water. -Jay Broyer Precision Pool Construction
water quality will be reduced
add some form of alkalinity booster for sure. bring it too about 110ppm, chlorine has a naturally high pH, but the higher alkalinity addition will stop acidic compounds from attacking the pH any further. depending on how low the pH is though you may have to add a pH booster, take your water into a pool shop for an in depth water analysis.
No shock needed after heavy rain however, you may need to add sodium carbonate. Rain water not loaded with essential minerals to maintain proper alkalinity of 100 ppm.thus, rain water may lower alkalinity and reduce available chlorine. Add baking soda to raise alkalinity and add chlorine if needed to the proper level of of 2 to 3 ppm
the chlorine increases the water purity .
Water has different alkalinities depending on where it's from and where it is.
p alkilinity is the minimal ppm level of alkilinity tested in boiler water, m alkilinity is the total (maximum) ppm level tested in boiler water.
80-120 ppm. If the level of alkalinity is low or high it can cause clouded water and pH fluctuation.
Well because rain is polluted water and the chlorine in the pool has a different pH level than the polluted water. Therefore, when it rains, the polluted water and the chlorine water combine and make a whole different solution or different pH level.