www.weedguru.com

The size of the plant (?) and the time vegging (6 to 8 weeks?); are they the main factor and are there other indicators to be aware of to help determine when to go to the 12 12 cycle.
thank you, gaw

Plant size and overall health should be looked at. Slow-growing plants that have been vegetating 8 weeks but are only 6" tall will need more time. About 10" tall with a strong main branch is the minimum to CONSIDER starting the budding process.

Take a look at some other grow sites and read some logs, observe when they put their plants in the flowering room.

You gotta think about how much room you have to grow...(mainly height)

Plants can triple in size once flowering kicks in, so you gotta consider that