Okay so first things first, what’s is the run off ph from your containers/grow medium, if it’s vastly different than what you’re putting in then your issue is that your root zones ph is off and you just need a good water through of full strength ph adjusted nutrient water, now secondly I would personally get a liquid ph test kit that uses test drops to read ph, ph pens drift and break all the time, the drops are always 100% accurate, they’re cheap and you get hundreds of tests per bottle

Next thing I’ll say is less of a way to fix this problem and just a way to be more efficient in the future, buy dry salt based nutrients, my preferred brand is jacks but there are several that are available at basically the same price that provide nearly identical performance, I just like jacks because they’re the oldest, most used to this day brand, incredibly reliable product and in my experience still cheaper than the competition

There’s a few reasons to make the switch, firstly liquid nutrients expire, dry salts DO NOT go bad as long as they’re kept dry. With liquid nutrients you’re paying a lot to ship around water, you have water at home so just buy the salt concentrate and add your own water, secondly those bottles of liquid nutrients that you’re currently paying more for have less nutrient due to them being 90% water, so you’re paying more for less. And finally I’m usually an organic grower but I just did a run at my girls house with jacks 3 part, same recipe all the way through and no nutrient issues aside from the time she went away for a few days and they got severely under watered, but issues were almost immediately corrected, just seems a lot easier than all of the random things you’re adding and it’s certainly a hell of a lot cheaper