1. Clean the probes of the meter after each test and wipe away any corrosion.
2. Pack the soil tightly around the probes.
3. Water soil with distilled or neutral pH water (7.0) before testing.
4. The meters measure the electrical current between two probes and are designed to work in moist soil. If the soil is dry, the probes do not give an accurate reading.
What causes fluctuations in pH?
When growing in soil any fertilizer you use can cause an excess build up of salts when it decomposes in the soil. This almost always results in a more acidic soil which stunts the plant's growth and causes brown foliage.
Other common reasons as to why soil may become too acidic when doing outdoor grows are rainfall, leaching, organic matter decay and a previous harvest of a high yield crop in the same soil.
In dry climates, irrigation water is often alkaline with a pH above 7. The water in rainy climates, such as the Pacific Northwest of North America, the UK, Netherlands and Northern Europe, is often acidic with a pH below 6.
Lightly sandy soils with little clay and organic matter are quicker too become more acidic. Another common mistake is that a grower will mix his soil unevenly, leading to "hot spots" in the growing medium, so mix all ratios as well as you can.
How do I raise/lower my pH?
A great way to regulate the pH of your soil is to use Dolomite Lime(calcium-magnesium carbonate).
Dolomite Lime works well because it has a neutral pH rating of 7.0 and tends to keep the soil a constant pH throughout the entire life cycle of the plant. This is a highly recommended method of regulating your soil pH.
If you find the pH of your soil to be too acidic or basic you could add either pH up or pH down. These are chemicals sold at places like a Home Depot or any Gardening store.
Some examples of Home remedies to raise/lower pH are as follows:
1.Lemon juice. 1/4 tbsp can bring a gallon of tap-water from 7.4 to 6.3.
2.Phosphoric acid. lowers pH and provides Phosphor too!
3.Nitric acid. lowers pH.
4.Hydrochloric acid. strongest way to lower pH
5.Hydrated lime. flush soil with a teaspoon per gallon of water to raise pH.
6.Baking Soda. eats acids to raise pH.
7.Calcium carbonate. raises pH (very strong)
8.Potassium silicate. raises pH.
What are signs of a PH fluctuation in my plant?
A plant can show signs of a pH flux in several ways. The leaves may begin to turn yellow or brown, dry up and/or shrivel on the sides into a straw like shape. Keep in mind however that other deficiencies and disorders may show the same signs of damage, so don't jump to conclusions until you do some testing and adjusting to your plants and their growing medium.
Some things to remember:
1.Always test the pH of raw water and drainage water with a pH meter.
2.Raw water pH above 6.0 helps keep fertilizer mixes from becoming too acidic.
3.The pH level is much more important in organic soil gardens than in chemical
hydroponic gardens. The pH dictates the environment of bacteria necessary to the
uptake of organic nutrients.