I'me fimaliar with most of the information in pool school and whatnot, and I've gone through the "HOw do I use chlorine in my spa"
I'm refilling my inlaws hottub for them and getting them off the regualr use of dichlor to the dichlor then bleach method. They had some messed up readings so draining it and starting over trying to make print out for new fill and for normal maintinance.
now in one part of it, it says to start with TA of 80 and fine tune depending on how the PH handles it. Then later it says you can figure the optimum TA based on using the pool calculator >>>>What should I do start at 80 or use the pool calculate to figure out, based on temp,Ch, PH and find the CSI equal to zero? Saying CH of 140, PH of 7.4, pool calculate says TA 110 is optimum. (CSI of -0.1) and a TA of 80 with those same levels would be -.24. Is the difference from -.01 to -.24 not as big a difference as it sounds and anywhere from 80 to 110 is good?SO, what's a good TA then? That depends on your CH. If your CH is around 150 ppm, your TA would need to be 80 ppm for your water to be balanced with an ideal pH of 7.6. How did I come up with those numbers you ask? Easy, I went to http://www.thepoolcalculator.com website, and plugged in a Temp of 100, CH of 150, pH of 7.6 and adjusted TA until the CSI was close to zero. This website allows you to calculate your Saturation Index, based on the four Main parameters, Temp, CH, TA and pH. If CSI is less than zero your acidic, if it's greater than zero your alkaline and of it's close to zero your balanced.