Nullis
Moderator
Who are you referring to exactly, who will see a build up or def and why?
It is indubitably confusing for new growers when they come here and scan posts for advice or methods or whatever, only to find it is mostly conflicting or even somewhat dubious. One can only be filled in so much about things like basic soil concepts\plant sciences, personal growing conditions & preferences, etc. in a single post. Rarely are significant positive results reproducible based per se upon any internet post alone.
All I can do here is try to reassure those first attempting to grow in soil\soil-less, especially with organic dry\liquid fertilizers, that using pH Up or Down to try to make your fertigation\irrigation solutions a perfect 6.5 or whatever is totally unnecessary. I mention the Down, but we all know that pH Up is the real culprit and both truly are marketed for hydroponics...definitely not soil! General Hydroponics pH UP is a very strong base (and a trade secret); it says on the product website it contains potassium hydroxide and potassium carbonate (and blue dye). While the MSDS says potassium carbonate and potassium silicate, with a pH between 12 and 12.3. The label itself says to "use sparingly".
However, the General Organics line, which was designed for soil\soil-less organics states right on it that adjusting the pH is not necessary: http://generalhydroponics.com/site/gh/docs/feeding_sched/GO-Feedchart.pdf
Earth Juice is basically the same story, despite that it is initially quite a bit more acidic (like 4.0 acidic), check out #12: http://www.hydro-organics.com/home/index.php?categoryID=556
Dolomite\calcite\pulverized oyster\eggshell are good supplements, not just because they help neutralize acidity, but also because they supply calcium. Dolomite is also mostly calcium carbonate, but it should have at least 6% magnesium content as well. Calcium and magnesium are needed by both the cannabis plant and microbes in the soil. Having just a bit more dolomite in your mix will help that initial drop in pH caused by mixing Earth Juice as is- and this is sustained each watering. According to the manufacturers info this drop is "primarily due to the natural phyto-acids and amino-acids contained in many of the Earth Juice formulas. These are considered "Weak" acids that will help transport (chelate) nutrients for easy and rapid use by the soil microbes and plants. Earth Juice will adjust and be conditioned by medium and beneficial microbes supported by the applications of Earth Juice."
The other better alternative is to aerate the fertigation solution for about 24 hours before using (or go the extra step of adding compost\humus for a real AACT). This will do a few things including increase microbial populations within the solution, conditioning nutrients for plant use and raising the pH of the solution (bacteria produce alkaline bio-slime). And with that, there is undoubtedly no need to be fussing with or obsessing over pH thinking you know what is best for the plant.
A keyword in that quote from the manufacturer info is "chelate". A chelate is a compound that forms a loose complex with a ligand such as a mineral ion, and in this case improves its availability to and transport within plants. Organic acids, in particular humic acids, play this [important] role in nature to allow plants to absorb nutrient ions it would not have had direct access too (iron in particular). This is largely why plants grow virtually everywhere on Earth, in all kinds of soils across various pH ranges (Blueberries 'prefer' it between 4 and 5!).
Hydroponics nutrients have replaced micro-biological assistance and organic acids with synthetic chelating agents, in particular EDTA.
