Well i was led to believe similar, above 8.5 and below 5.5 may shock the roots a little but as for pH well i believe that is determined by the parent material or soil in our cases.
I feed at just above pH8 some days and generally i never get lower than 5.5 at worst and have not a single problem. By pH'ing the water you are basically cancelling out acid and alkali ions with either acid or alkaline.
Its overcomplicated and in most cases unecessary, if your tap water is outside of these ranges i wouldnt recomend drinking it let alone give it to a plant. I have yet to fully understand the whole topic of pH but with all the misinformation it is hard to get to the bottom of it.
Now i was always told that soil and water are two different things when growing in soil, soil pH is determined by acid hydrogen ions which build up and are even added to the soil from the roots as a byproduct of fertilizer uptake. Now because of the soil cation exchange capacity these can be replaced by alkaline ions from calcium and magnesium and one or two other alkaline elements making the soil less acidic and less hydrogen ions will be loosley bound to the soil particles, exchanged by alkaline ions hence the exchange in cation exchange capacity.
Now to add more alkaline ions to the soil to stop it from becoming acidic we use a buffer generally lime which is calcium or sometimes calcium and magnesium both are alkaline and hence will exchange with the acidic hydrogen ions making the soil more alkaline. The excess hydrogen ions seem easily flushed from the soil.
Now i do believe for the reason that water contains very small amounts of alkaline ions such as calcium and magnesium as well as potassium which i believe is also alkaline that it can affect soil pH although this takes a long time and not really of too much concern in a typical soil grow.
Simply put you can add lime to your soil and it will buffer it, low or high pH water has little short term effect.
Anyone else wana chime in with some ideas or knowledge on soil pH or question my method of understanding soil pH is more than welcome, we need to discuss this and stop all the myths from spreading. Peace
It's a tough subject to understand, I don't think I ever will understand it.
But you seem to have similar "understanding" as me, that it's the plant roots - in reacton to the soil and liquid nutrients - that are what really dictate the PH of your growing medium. The water-PH has little effect, in comparison (and this is why they say PH doesn't matter in compost).
Of course PH matters, it's just that we don't have to think about it, if using correct compost and nutrients.
Take a look at your "grow"-bottle, and see how much of your Nitrogen is in ammoniacal vs Nitrate form.
If mostly ammoniacal Nitrogen, your medium will get more acidic.
If mostly Nitrage Nitrogen, then it will get more alkaline.
So the PH of your grow-medium is set mostly by the compost and whatever liquid organics you choose to feed it. IMHO.
Source:
"
When ammoniacal nitrogen is taken up by roots, the plant
can secrete an acidic H+ into the soil solution. The more H+ contained in the root media, the lower the media
pH.
Urea is easily converted into ammonium in the substrate and therefore
can be thought of as another source of acidic nitrogen.
In contrast, uptake of nitrate nitrogen increases substrate-
pH because basic OH- or HCO3- are secreted by plant roots into the root media. Since OH- and HCO3- are bases, nitrate uptake therefore
can cause the media-
pH to increase.
"