Ok, I did the same thing that most of us did, believed the "Pool Guy". He said I had to get my chemicals from him, and that only he was "qualified" to test my water. He said don't use those "other" chemicals you can get from Wally World as they are inferior to his and contain stuff you don't want in your pool. Heck, he even told me that using bleach would only last about 5 minutes in the pool.
And then ..... I saw error of my ways. I ordered and received my own test kit (a TFT TF-100) and found that bleach lasts longer than 5 minutes.....
I did my first test:
I plugged those numbers into the handy dandy... Pool calculator, and was rewarded with the info that I needed a whopping $2.50* worth of bleach, and some aerating to lower my TA. To think, he said I needed $50.00 worth of shock/chemicals to do the same thing..... silly pool guy, tricks are for kids....
* your price may vary, not applicable in all states. Tax tag and dealer prep extra..... or wait sorry, wrong commercial.