The pH value of a solution is a key chemical characteristic and can largely affect plant health. For plants, the pH of the soil can drastically alter their productivity because hydrogen ions play an important role in photosynthesis. pH adjusters are often used to treat soil and ensure plants stay healthy and continue to metabolize nutrients and create energy.
Most plants have some level of tolerance to small shifts in pH balance. However, as the plant becomes more stressed by much higher/lower levels outside of its tolerance, its health will greatly decline and it will likely die if strained conditions persist, or if it is immediately exposed to a toxic level.
pH in a Nutshell
pH value measures the concentration of hydrogen ions in a solution and rates that concentration on a scale from zero (acidic) to 14 (basic/alkaline)
Acidic Substances: vinegar, lemon juice
Alkaline/Basic Substances: lye, milk of magnesia, and ammonia
Pure water is neutral with a pH of 7
Each whole pH value below 7 is ten times more acidic than the next higher value
Substances called buffers may be applied to solutions to adjust the pH
Mixing acidic solutions with alkaline solutions can cancel out the two extreme chemical properties and create a neutral solution
When mixed with water, a chemical mixture can become either acidic or basic
The concentration of free hydrogen ions is what is specifically measured by the pH scale:
H+ and OH- ions are present in any solution (liquid) at all times
If base ( OH-) is added to water, the H+ concentration decreases- this makes a solution more basic
If an acid (H+) is added to the water, the OH- ion concentration decreases- this makes a solution more acidic
The pH Scale
An acid is a molecule that donates hydrogen ions. Acids increase the concentration of hydrogen ions in a solution.
A base is a molecule that donates hydroxide ions or binds excess hydrogen ions. Bases decrease the concentration of hydrogen ions in a solution.
Buffers are substances that prevent a change in pH. They accomplish this by absorbing or releasing hydrogen or hydroxide ions.
Measuring pH
Litmus paper (pH paper) is a type of paper treated with a dye that changes its color as the pH of the environment changes so it can be used as a pH indicator. Electronic pH meters can be used to make more precise measurements of pH, and special meters can be used for soil to measure pH and moisture levels.
Soil pH & Moisture Meter
Professional pH and moisture meter
12 in probe
Can measure pH and moisture at depths up to 12 in
No batteries are required
Meter comes with a cleaning pad.
Digital Waterproof pH Meter
Measures pH and temperature
pH buffer 4 solution is in a sponge embedded in a clear cap
Measurement range: 0-14 pH with waterproof housing
Digital automatic calibration (one point), with digital fine-tuning
Auto-off, data-hold functions, and low battery indicator
Adjusting pH
If you need to correct pH, you will need a product like pH Up or pH Down. These solutions allow you to quickly adjust the pH of your nutrient solutions without adding anything that will alter the nutrient formulation. pH balancing your nutrient solutions is a fast and easy way to avoid more complex issues and makes nutrients more available to plants.