Bigger baskets would be for plants that are going to be larger in size. Like if you were going to veg longer than usual. Stability is the reason for the different size baskets. Example: if you were to veg a plant for 8 weeks in a six inch basket, your plant might over grow the basket creating an unstable base. Whereas you veg for 8 weeks in a ten inch basket, the plant would be stable. Less veg time - smaller basket. Longer veg time - bigger basket. Make sense?

CGI::::::