Put another way, you control the pH of what goes into your pot; your plant controls the pH of what comes out of your pot. You and your plant need to work together to make sure that the pH of the soil (The runoff is going to be just about the same pH as the soil) stays within the prescribed parameters. This is accomplished by providing the plant with proper nutrients in a properly pH'd solution.

If the plant starts reacting negatively to its growing conditions, primarily what you are feeding it, the pH of your soil will change. Inversly, if you screw up the pH of the solution you are feeding the plants, the plants' health will suffer. So, if the pH in your pot is off, you have to determine who is causing the fluctuation, you or the plant. Once you determine the cause of the problem, then you take remedial measures to correct it.

The entire pH issue is much more complex than this, but I hope this gives you kind of an overview of how it works.

PC :smokin: