Million Dollar question

I see so many people asking this question as a first time grower and really do understand why.
This is my first grow and I want to make sure I harvest at the right time.
I am growing super lemon haze from green house seeds. Says 60 to 70 days. I switched to 12/12 60 days ago and saw pistols about 55 days ago. I do have a loop and did see a few amber trichomes on a couple of buds. Some of the bottom leaves are dying off even and i havent changed my watering schedule, just a change in the flora trio. They didnt like the change as this was my first bit of nute burn. Water about every 3 days in soil with nutes every other watering.
I have attached a couple of pics taken today. Not the best but any suggestions would be appreciated.
 

Attachments

Top