pH measurement, and how to fathom it.
I notice on some messages to this forum that some people are perplexed about pH, and how to fathom it.
Here is a thumbnail sketch that may help some people, without getting too technical.
Acids are acidic and low in pH. For example Sulphuric Acid and Hydrochloric Acid are highly acidic, whereas Citric Acid, Tartaric Acid and Acetic Acid are relatively weak acids, as are most organic acids.
Bases are alkaline and high in pH. Sodium Hydroxide (Caustic Soda) and Potassium Hydroxide are quite strong bases, whereas Sodium Carbonate (Washing Soda) is relatively weaker as an alkali. Ammonia is a moderately strong base.
It is important that you grasp the following concept as it should dissipate much of the mystery about pH measurement.
A pH of say 5.0 is TEN TIMES more acidic than a pH of 6.0
For all intents and purposes, a pH of 7.0 is regarded as neutral, i.e., neither acidic nor alkaline.
A pH of 10.0 is TEN TIMES more alkaline than a pH of 9.0
The pH scale is what is referred to as a Logarithmic Scale.
Now for pH meters. Please make sure you have a reliable pH meter and know how to calibrate it properly. If your pH drifts off too far, you will find that your plants are not growing as strongly as you would like them to. This has got a lot to do with the availability of Iron in solution.