Ditto everything Weezard said and I will add that keeping the pot/rootball size ratio fairly small forces the plant to use the resources in the soil. In extremely soft soils (like potting soils) the rootlets can grow very fast and when they stretch their absorption efficiency declines and they become weaker. Confining them forces the roots to mature and use the available nutrients completely. Once the root density becomes high, putting in a fresh zone of soil allows the plant to grow rapidly. After you have done this several times, you will have a plant with a root system that is very mature and dense. Just in time for flowering.:smokin: