This is a properly buffered soil right?

What does buffered means btw? That it let soil ph and water ph equibilirate or that it takes down water ph all the way down (or up) to soil ph levels?

I had some issues in mid/late flowering with necrotic yellow spots on leaves on some autoflower plants and it seems to be "P" deficency.
having 8.2 ph tap water which i used every second watering during flower and every watering during veg I naturally though it was a ph issue, bought ph down and ph meter.
Measured the runoff water from both new unused soil and the soil I currently having 9 weeks old plants in, BOTH soils gave me around 6.5 ph runoff water when watering with 6.5ph water AND 8.2ph water.. so: 8.2ph in -> around 6.5 out, 6.5 in -> around 6.5 out.

Measured by having a big "cup" of soil in my hand and letting water drip through slowly.

The fert I have been using before was 3 1 4.

Am i correct assuming PH adjusting my water is 100% useless and that by using Hesi bloom komplex with 3 3 4 during flowering will solve my issues with yellow necrotic leaves later flowering on some plants?

Edit: here is pictures of plants 1 week ago or 2 https://www.rollitup.org/marijuana-plant-problems/758080-need-help-2-7-plants.html#post9914839

Yes, pHing your water is pretty much useless as you showed yourself.A well limed (pH buffered), soil will get the waters pH to its (the soil), pH and not the other way around.Wet

11-5-18 fertilizer doesn't sound particularly organic. What does the front of that bag say?

Whatever it is, it will benefit from some compost or worm castings. Not only will that add a great deal of buffering ability to your soil, it will also bring it to life. There is more to healthy soil than peat moss, gravel, lime, and fertilizer.

pH is definitely less important in organics, but you NEED some form of humus in your soil mix for that to work.

A "buffer" is something that is resistant to pH change. in soil, that would be the lime, in water that would be dissolved solids like calcium carbonate. Well water resists pH change better than distilled.

Soil itself is said to have a buffering capacity, it relates to cation exchange capacity which can be thought of as a pool or reserve of both nutrients and acidity (as H+ is a cation).