Well, Z, if you really are looking to attain certification, you've got a lot of reading to do, and that's just to start! It's really about record-keeping and planning as much as anything else, and after the problems we've experienced in our food chain with fresh veg & fruit (Listeria and E. coli, etc) that have resulted in deaths, I no longer bitch about the government, its 'interference' or the need for all this God damned motherfucking paperwork. I grasp, fully, why it's needed, because I tell you what, if it were one of *my* loved ones that died or became very ill I would be expecting my government to be able to figure out what happened. Not going on like what's happening in China with the fucking dead pigs floating down a river. Tens of thousands of dead pigs, and officials say, "Oh! the water is perfectly safe to continue using as your drinking water." Uh huh. And the check's in the mail, too, you swear.
Jesus, that was a rant. Hey, you didn't just start tokin' a joint, too, didja? ~~=== <--- I have no idea what it is. I've got a very few branches of last year's harvest that I was allowed to keep by the... what do I call them? Rippers? That's too mild. Robbers? Oh well. It's got some good purple in it, but it wasn't marked, so hell if I know what it is.
But basic to know about doing the organic farming/production is that here in California the farm is both registered with the state as an organic farm, either certified by an outside certifier (CCOF), or following organic methods and practices and backed up by farm records. I can see this nicely dovetailing in with our new cottage food production law, which many would argue goes against what I just discussed above. I still think it can be done, and be done safely.
Ok, so.... onto pH adjusting your tea--IMO if it's always landing at 6.4 that's exactly where I would leave it. But, if it doesn't, then I would handle the adjustment in one of two ways--I would either sacrifice some of those microbes, take out a gallon or two and put the adjuster in that, then add it back (this works best if you know volumetrically or by meter exactly where to pH that body, or how much to use) to the main column, OR I would simply use some more water to add the pH adjuster, and then add that back to the tea.
Know that high NO3 levels in plant tissues are demonstrated to result in diminished flavor and Brix. I'm only just beginning to play around with plant sap pH levels and Brix as a method/means to achieve best quality plants. I'll let you know if I ever hit the point where I can discuss it intelligently. There's a really good video that I saw a couple of years ago or three that I've spent the past... 20 minutes trying to find, and I can't. Just start searching on Brix as a measure of plant health, and then plant sap pH. I've read a good bit, I'm just not grasping the whole picture very well.