I've posted this other places, but I'm gonna add it here. I think one of the biggest factors that people get confused on with flowering time is when it starts. I'm always seeing newer growers asking if their buds are done, and/or why they don't look full and finished.
Flower does not begin when you switch your lights to 12/12. It is a hormonal response within the plant that takes time. After you switch your lights the plant must go through a "transition" phase. It reacts internally to the light change and builds up the appropriate hormones to begin flowering. If the plant is fully mature, like a clone from an established mother, this transition will usually only take 4-7 days depending alot on genetics.
However if you attempt to switch a plant to flower that isn't mature it can take much longer for it to transition and actually begin to flower. Some times this lack of maturity can add weeks to the transition. The genetics again play a factor here. The genetics determine how long it takes for the plant to mature, and will impact how long it takes to transition. All of this as well as phenotype variation is why its hard to go by an advertised "flower time". The breeder might be right on that one phenotype under perfect conditions will actually flower for 6 weeks and another might be 8 weeks but that should be actual flower time not just time spent under 12/12 lighting.
Like everyone else without seeing your plants I can't begin to say whats actually wrong here. It sounds to me though like you have some different phenotypes in the mix which can result in very different plants even from the same seeds.
I would also guess (and this is why I typed every thing above), that you are trying to count on the plants switching to flower when you flip the lights to 12/12. If the buds look like the pictures you did post, then they are likely only about 2-3 weeks into the flower process to begin with. If you only vegged the plants for 1 month prior to flipping then I highly doubt the genetics were mature and inturn it took those plants extra time to transition before beginning to flower.
It sounds like you've got alot of money and time put into this grow so I hope your able to work out the kinks.
