Sometimes it's just a plain hoot to sit back and watch....
Guess I'll add a cpl of points to ponder.....wtf right?
By simply watering with that pH of 4 solution. IF you don't allow that soil to properly dry back out between watering's.....
You very well could start to get a pH problem...
If you want to throw money at the problem and not worry.....Spend on organic pH products.
As far as Up's or Downs wrecking organic nutrients...... Not really more so then synthetic nutrients and pHing does.
Up it if you like.
Personally speaking. A pH value of 4.0,,is pretty low for me.....I might up that to mid 5's and let the soil do the rest from there.
Things is, keeping a good living bio heard is important to not adjusting pH values and simply pouring it in. If, you begin to get a pH problem.....I'll put dimes to dollars your bio heard is not healthy!
Over feeding and underfeeding --- does effect the heard.
It should be that you shouldn't "have to" add more. But, at about every 3 - 4 weeks is a nice idea.
I brew my own simple Bio Teas (AACT). These are watered in every month,,,,See a possible issue starting?
I'll drop some in at that time and see what the plant tells me in 5-7 days.
I like a "fungal heavy" spectrum. I have little mushies grow out of my soils as the plant grows. They continue on after harvest (till the soil really dry's out) too.
I kinda use them as an overall health of the heard indicator.....Not scientific, just something I've adopted along the way, over the years.
KIND is right! pHing run off is not an indicator of ANYTHING but, the pH of the runoff!
Skip that shit!