New pool owner here as of last year. I decided to start the TFCP method this season after messing with 4-in-1 chlorine tabs and Shock last year (so far just adding Clorox Bleach from Costco for chlorine) and here are my before/after results using the TF-100 test kit when I replaced 50% of my water:
Total Chlorine (FC+CC):
Calcium Hardness: 700 ppm
Total Alkalinity: 180
2014-05-19 drained 50% of pool and refilled
Chlorine: 3 (just added 121oz Chlorine an hour before testing)
Free Chlorine: 4 ppm
Combined Chloramines: 0
Total Chlorine (FC+CC): 4
Calcium Hardness: 625 ppm
Total Alkalinity: 170
So my pH, CH, TA, and CYA came closer in line, but are still out of whack. My main concern is having my chlorine levels burn off in three to four days which leads to the beginning stages of algae forming on one end of the pool wall.
With AZ water being so hard, how can I get my CH, TA, and CYA lower? The Pool Calculator still tells me I should replace 58% of my water to come in line with CH and replace 43% to lower CYA. I know I need to lower CYA and pH to allow the chlorine to last longer, but I'm not too keen on replacing 50% of the water for the second time in a single month. Thanks for your guidance.