First, I know in soil you should have a 6.5 - 6.8 Ph level, but what about when your water/fertilizing your plant, what should the Ph of your water be? Finally, when testing Ph level's of your Run off, are the run off ph levels going to be lower or higher then your original Ph level you started out with? And how much does the Ph level decrease/increase?
you need to buff your feeding water to get it to that 6.5 to 6.8 level. when you add fert to water it pushes that ph up and you need to add a buffer to get it down. The ph of your run off depends on how often you feed and if you buffer. if you have been feeding but not buffering that water then the runoff will be high