while it sounds good... it's not entirely true. I've come to the conclusion that there is a relevance of pH even when growing organically. If your pH approaches neutral throughout your entire pot, you have decreased solubility of key minerals like phosphorous and your photosynthetic catalysts (Fe, Mn, Zn, Cu, etc). Now your microbes may assist in the breakdown and delivery of some of these nutrients, but the solubility of these nutrients is still relevant because you want mineral diffusion to happen in your soil. The microbes can assist in delivery around the root zone... but you still need to be able to use water to mobilize nutrients throughout the medium because there are some that are in plant available form.
I've experienced this first hand. Massive decreased yields when pH is not on point. Get pH right (usually by starting a fresh mix) and boom yields back where they should be.
Another thing I'm discovering... pH of rain water is around 5.6-5.7 due to formation of carbonic acid in the atmosphere from exposure to CO2... so when pH is creeping up in a container, I see no issue with adding some citric acid crystals to lower the pH of the water and offset some of that alkalinity (which comes from CaCO3 most often). Neutralize the base with acid (which also creates available Ca) and lower the pH back where it should be.
Some will not share this philosophy... but pH is most certainly relevant IMO.
