Our pool will be closed next week by our usual pool company. For the first time at opening, I instructed them not to add any chemicals as I now add them myself, thanks to BBB I know I have to shock for a couple days and bring down my PH (it was a little high at todays check)and add Ployquat. Do most pool stores have that? Is it called Polyquat and how much do I need? Thanks in advance.