Well, BrownDirtWarrior mentioned Advanced Nutrients Heavy Harvest. You should do a little research on it. The information sounds pretty good. And, as far as the size hole you want it depends on you. How big do you want your plant to get? How often are you able to water. Soil is KEY!!! It should drain well, have good aeration to promote root growth, and have plenty of readily available nutrients to help it grow. How often you are able to get to your plants plays a role in these things. From my understanding it could be the difference in having a small yield versus a big one.