Sapphire:

Listen to Jan and Lisa! As long as you keep going in to that pool store they are gonna keep selling you junk. Sometimes it will be useless, sometimes it will make things worse, and sometimes it will an expensive package of something you can get really cheap like the "Alkalinity Plus" for an insane price. The pool store lady was right--the "Alkalinity Plus" HAS something baking soda doesn't--a highway-robbery price.

Washing Soda raises pH and Total Alkalinity. If both are low, it's good stuff--and it's the same as the fancy pH increasers that pool store lady will sell you--far cheaper.

Pool maintenance is simple, and even clearing up pool problems usually is simple too. But letting you know that is NOT how pool stores make money.