Why shock level is recommended for closing?
If you have solid pool cover the high clorine level is bad for the cover and will shorten its life. If you add algecide and closing in colder temperature, it will be ok without shock level, no alge will grow
If you have solid pool cover the high clorine level is bad for the cover and will shorten its life. If you add algecide and closing in colder temperature, it will be ok without shock level, no alge will grow