pH Explained
pH is a measure of the degree of the acidity or the
alkalinity of a given solution as measured on the pH scale of 0 to 14. The midpoint of 7.0
on the pH scale represents a "neutral" solution which is neither
acid nor alkaline based. Numbers below 7.0 indicate an acidic base and numbers greater than 7.0 indicate
alkalinity.
It is important to understand that pH is a measurement of intensity, to use an everyday comparison
" pH indicates the intensity of alkalinity in the same way temperature tells
how hot something is - but not how much heat the substance carries."
The pH scale is logarithmic which means that moving
on (unit either way on the pH scale results in a 10 fold increase in the degree of
alkalinity or acidity).
Some typical
pH values are included in the following table
|
pH |
Product |
|
0-1 |
hydrochloric,
sulfuric, nitric acids |
|
1-2 |
phosphoric,
sulfamic acids |
ACIDIC |
2.0 |
citrus
fruit |
|
6.5 |
milk |
|
|
|
NEUTRAL |
7.0 |
|
|
|
|
ALKALINE |
8.0 |
eggs |
|
11.0 |
ammonia |
|
13-14 |
caustic
soda, floor strippers |
As a general rule of thumb,
cleaning performance on typical oily soils is enhanced with an increase in pH.
Some soils, for example hard water deposits, are best removed with acids.
Products at the
two extremes (less than pH 1 or greater than pH 13) are extremely oppressive
and corrosive. Examples include sulphuric and hydrochloric acid on the acid
end, and caustic soda on the alkaline end. Use solutions of phosphoric or
sulfamic acid cleaners, typically in the pH range of slightly less than 2, may
be described as "safe" acids comparison to the stronger acids. Of
course, necessary safety precautions (eye and hand protection) as noted on the
Material Safety Data Sheet should always be followed.
As an illustration of their
non-aggressive behaviour in comparison to stronger acids, products containing
sulfamic or phosphoric acid were found to result in no chemical attack on nylon
carpets. On the other hand, a hydrochloric or powder acid-based product would
basically dissolve the fibres.
Other than the two pH
extremes, the pH scale becomes secondary to the inherent properties of the
specific chemical in terms of corrosiveness. As an example, the pH of
carbonated cola soda (which contains phosphoric acid) is in the 2.5 range. A concentrated
(35%) hydrogen peroxide solution has a pH of approximately 3.5. Carbonated cola
soda may be slightly irritating to the eyes, causing no permanent damage.
However, a 35% hydrogen peroxide solution will cause chemical burns to the skin
or mucous membranes. Thus, it is not the pH factor alone that causes corrosion
of products to surfaces.
Relative pH info for Growers
Now you have a
complete understanding of what pH represents it's time to get into a bit more
info that relates to growers. As shown above pH is represented by a numerical
scale that expresses the acidity or alkalinity of a solution (in our case the
water in our reservoir).
Marijuana thrives in slightly acidic mediums. Soil and soil less mixes should
aim for pH of 6-6.4 and hydro growers should go slightly lower which
helps prevent pythium and other root rots 5.5-5.7 is an ideal starting point
allowing it to fluctuate up to but not over 6.1. The reason this information
about pH is so important is because of the availability of different minerals
needed by the plant to grow changes at different pH levels. This is best demonstrated
by looking at the chart bellow that I found on the Forums which outlines the appropriate
pH range for growers and what minerals are available at the different pH levels
in that range.
Tutorial written by Pure for cannanation.com/ozstoners.com