After a rain I really don't do much besides adjust pH back into a 7.4-7.6 range if needed. If I have a high bather load, I'll run the pump longer for a day or so. My Cl level stays pretty consistent without much adjustment to the Autopilot controller. (33% for a SC-60 to maintain 3-5 ppm FC at 60 CYA and 8 hrs pump run time/day in my 19,000 gal IG vinyl pool).