In the past I have always vegged for 1 or 2 weeks, but I am currently testing 3 and 4 week veg times. I run my lights 18 on and 6 off. I have also noticed the taller pots grow the plants more vertically. I am currently experimenting with root maker pots and air pots. I have 2 gallon, short, root maker pots that vegged for 3 weeks and 3 gallon, tall, air pots that vegged the same strain for 2 weeks. The plants in the 3 gallon pots, which vegged one week less are taller, have thinner stocks, less foliage, and buds are spaced further apart.