I have a relatively new pool (a little over two months of water). During the second month a Pentair IC-40 SWG unit was started up. Due to a miscomminication between the equipment setup guy and the company pool service the filter was cleaned not long after CYA was added. As a result the first 10 days or so I had a CYA level of about 40. The SWG had to be run at a 60% duty cycle to keep FC at the target level (set for a CYA of 70). After correcting the CYA level to 70, I have been able to turn down the IC-40 duty cycle to 25%.

This is for a pool receiving direct sunlight from dawn to dusk, space coast area of Florida.