Should I keep my light hours or take it back down?

DLI, DLI, DLI (daily light integral) It is not about hours of light. that is an incomplete perception. Rate x time = DLI. It's about photons per day, not hours per day. If you were providing a proper amount of DLI with 20h, you should go back to that... or 16h or 18h, whatever provides ~35-40 DLI. Local variables will impact exactly how much you can give and will be different than the next garden, but not too much given basic competency. use the umol/s PAR spec from your light. you need roughyl 80umol/s per sq ft for 12 hour operation. It is inversely proportional to hours of operation so you can adjust that '80' to fit any hours of operation. Doesn't matter if they are autoflowers or photoperiods in regard to max DLI. Still the same starting point and you adjust based on growth pattern, not whimsy. too tight? adjust power down. too lanky? adjust power up. 80umol/s PAR per square foot over 12 hours will get you to ~37 DLI. 2/3rds of that over 18h also gets you to 37 DLI. As far as growth and yield, DLI is what matters.. not watts or hours of operation. common sense required for light distribution and other concerns...