Hello everyone my name is David, bought a house last year in June of 2020 with a in-ground 12,783 gallon vinyl liner pool. Has a cal spa right next to it. 425 gal hot tub. I use to bring my pool water to Leslie’s all the time and kind of guess it with my strips. Never really had much issues, used a lot of dichlor last year to chlorinate and trichlor in the winter. Just got a tf-pro and will be going less to Leslie’s.