Something broke or the power went out. Don't panic. Follow this in order based on what failed.
Under 4 hours: minimal impact. 4-12 hours: stress possible, monitor. 12-24 hours: significant risk in flower. 24+ hours: potential crop damage.
⚠️ In flower: treat the outage as extended dark period. When power returns, start the light cycle as if it's "morning." Do NOT add extra light hours to compensate.