pH is the single largest limiting factor in nutrient availability. All plants have a predetermined maximum genetic yield potential. There is no such magic product that can increase yields beyond this genetically predetermined limit. Therefore, the variety of strain and phenotype, and the health of their genetics (mutation-free), is the most crucial consideration when determining Key Performance Indicators (KPI’s) for each growth phase and ultimate yield projections.
Traditional pH down products in horticulture primarily use phosphoric acid. This is perfectly fine; however, we must consider when calculating the total ppm of your growing solution. When adding to the reservoir, one slip-up can add a significant amount of phosphorus when you play the yoyo going back and forth trying to hit your ideal pH.
For example, taking water from 7.0 to 6.2 with alkalinity of 1 meq/L, adding the required 0.4 ml per liter of a 60% Phosphoric acid product, can significantly swing the balance of elements out by adding over 18 ppm of phosphorus. Consider cannabis plants’ Phosphorus limit is 75 ppm, and with most fertilizers programs supplying close to that level, you can easily get in the way of your plant’s success very quickly.