Finally figured out why my FC kept dropping every afternoon

Small one but satisfying. Been chasing FC drop from about 5 ppm down to 2 by late afternoon for weeks, blamed the cell, blamed CYA, even pulled the Sigma early thinking it was stirring up demand. Turned out my salt cell schedule was running its full output in one block overnight and sitting idle most of the day, so UV loss from the sun had nothing to backfill against. Split the run time into two shorter blocks, one midday, and now I'm holding steady around 3.5 to 4 ppm all day without bumping output percentage at all. Same total kWh into the cell, just timed better. Felt dumb for not checking the schedule first instead of the chemistry.