Hi and WELCOME to The Forum!!

What usually causes this is a combination of greed and ignorance on the part of the pool store.

A contributing factor is your own ignorance

However, this can be corrected

My prescription to you is to get to know your pool (we'll help and answer [U]any[U] questions you have). To do this you need to read through The Forum (& the Pool Solutions site) to get a basic understanding of what's going on with any pool - viewing the 'stickies' in any area of interest should be enough to start.

Next you need to get a GOOD test kit and test the water for yourself (there are links in the Mods and Pooldoc's signatures) [unless you've been backwashing every other day, you shouldn't need more cya (stabilizer) and calcium every 2 weeks]

I know that it's intimidating at first but, you can quickly and easily learn how to care for your pool with a good test kit and the knowledge we proffer.