Sounds like you already have your solution, I'll just comment one the light changing process your used. I rotated my lights schedule from daytime hours to nighttime hours and I found that adjusting the light schedule 30 minutes at a time per day was no problems for the plants. Just like you said, in nature the lights don't change that drastically, so I moved lights on up 30 minutes and lights out up 30 minutes each day until I arrived at the times I wanted. I run 18 hours lights on and 6 hours of lights out.