That can only come from trial-and-error. There are too many variables affecting FC consumption to make an easy formula. UV varies considerably throughout the year and the latitude, and even if you get a lot of fog or clouds. Temperature affects it as well. So does usage - a pool that never holds any dirty bodies will use less than one that has dozens of children. And then there's the amount of organic debris that the chlorine tries to oxidize.09659 said:
By the way, just to be clear, a lot of the information in Bob Lowry's article you reference came from me as he took some of what I wrote on (mostly) this forum, modified and organized it along with adding some other material (such as charts he made on TA buffering using my Pool Equations spreadsheet), and had me review it. And of course, Ben Powell came up with the original Best Guess Swimming Pool Chlorine Chart that I used along with the chemistry of chlorine/CYA to come up with minimum FC/CYA ratios to inhibit algae growth (with a later modification at a somewhat lower level for SWG pools).09659 said: