when to flower

Is there a certain height that you should reach before you should start flowering. I am using 4 42 watt cfl untill my lowryders are done under my 400watt light. planning on getting more cfl's if i need them. plants are about 3'' tall in 12 days. is that a decent grow rate, or is that slow.

It all depends on the size of the space you have or the yield you want to expect from your plants. I would say minimum 30 days of vegging. IMO