I see a lot of wild claims, and some insane theories. Fox Farms says "I'm no scientist, but the Ph will cause the bacteria to die if you change it too rapidly" Other tel you the solutions leave salts that cause problems. So, what's the truth?
Well, you're adding in materials that literally break down to create more nutrients. So, right there, I think I've debunked the "it creates microsalts (never heard of that one before today) that can cause problems. Now, for the bacterial? Well, imagine carrying 300 pounds on your shoulders, and made to keep on your feet or die. Suddenly, someone just lifts that weight off your shoulders. Or like for any extreme environment, anything that doesn't kill you often can be recovered from.
Usually, bacteria can grow well. Granted, if you adjust it too radically, you could have problems. But, even if half the bacteria are killed off, it's bacteria. 1 bacterium can multiply to trillions within hours. And to be honest, adjusting the PH to the usual grow ranges, all you're going to see is the bacteria you want finding a friendlier environment, and recovering quickly. It's like lifting all that weight off someone's shoulders. They'll catch their breath, wipe their head, and go on, recover, and be ready to kick some.
The moment someone makes grandiose or off the wall scientific sounding babble, stop and ask questions. do some research. ask for their facts sources, or research data. Otherwise, you'll wind up chasing your tail. I've heard wild claims from Colloidal silver activating some kind of quantum field, or that jackhammering your feet will cure psoriasis, or vitamin c or aspirin curing cancer.
I speak more from microbiology and science, since the facts are easy to look up, just burred in a huge pile of useless nonsense and even dangerous ideas recommended as just fine and safe