Cannabis pH: What You Should Know
Cannabis pH is an often-overlooked factor that can significantly impact the health of cannabis plants and the quality of their buds. Incorrect levels can lead to nutrient deficiencies, stunted growth, and a wide range of other issues.
By maintaining the ideal pH for cannabis, growers will be one step closer to cultivating healthy, vigorous cannabis plants that produce high-quality flowers. This article will describe what pH is, the best pH for cannabis, and how to test and balance pH levels.
What Is pH?
The term refers to how acidic or alkaline something is. The pH scale ranges from 0 to 14, with a value of 7 being neutral. Values greater than 7 indicate alkalinity, and values below 7 are acidic.
To be more specific, it is a measure of the relative amount of free hydroxyl and hydrogen ions within a substance. The more free hydrogen ions a substance has, the more acidic it is. Conversely, the more free hydroxyl ions a substance has, the more alkaline it is.
The scale is measured in logarithmic units, and each value from 1 to 14 represents a ten-fold change in the acidity or alkalinity of a substance. For example, a substance with a value of nine is ten times more basic than a substance with a value of eight. This means that a variation of just one point could significantly impact the health of cannabis plants.
Best pH for Cannabis
The acidity or alkalinity of a growing medium or nutrient solution can affect the growth of a cannabis plant. This is because cannabis plants can only uptake nutrients within a specific range. In general, Cannabis plants perform best when cultivated in a slightly acidic environment. However, the best pH for cannabis plants primarily depends on the medium used to contain the plants.
Cannabis Soil pH
Areas where cannabis grows naturally tend to have acidic soil. As a result, most cannabis strains have adapted to thrive in slightly acidic soils. The best pH for cannabis grown in soil is usually a window of six to seven. This range will allow the plants to absorb the optimal amounts of nitrogen, potassium, phosphorous, calcium, magnesium, and many other macro and micronutrients.
How to Test Soil pH
When growing cannabis in soil, it is important to test not only the nutrient solutions being fed to the plants, but also the soil itself. The easiest way to test soil is to use a pH probe or soil test kit. If you do not have a soil test kit or probe, you can make a slurry of water and soil and use a pH pen or strips to test it.
If the soil falls within a range of six to seven, you likely do not need to make any adjustments to it. However, if the soil is significantly above or below this range, you will need to balance the medium.
If your soil is too acidic, there are several ways to correct the issue. The first method is to mix a small amount of pH up solution into your water and flush the soil. Test the soil and repeat the process every few days until the medium falls within the correct range. Another method is to mix dry ingredients such as lime or wood ash into the soil. These materials will adjust the acidity while also providing additional nutrients to the plants.
If your soil is too alkaline, you can water the plants with a pH down solution until the medium falls within the correct range. Another technique is to mix compost, pine needles, or worm castings directly into the soil. Again, these ingredients will reduce the alkalinity while providing an extra supply of nutrients.
The ideal pH for hydroponic and soilless media is a bit more acidic than for soil. When cultivating cannabis in a hydroponic system, a range of 5.5 to 6 is optimal. Because these types of media are inert, they do not supply the plants with any nutrients. As a result, the cannabis plants must be fed with nutrient solutions that are properly adjusted.
How to Test pH of Water
Whether you are using soil, soilless, or hydroponic media, it is always a good idea to adjust the pH of your water before feeding the cannabis plants. The easiest and most accurate way of testing the water is to use a pH meter or pen. Simply turn on the pen, insert the tip into the water or nutrient solution, and slowly stir until you get a stable reading. Use a small amount of pH up or down to make adjustments, and test again.
Another method is to use pH strips. These are inexpensive and easy to use but may not provide the accuracy of a high-quality pen.
Cannabis pH Problems
Improper pH can cause a host of problems for cannabis plants. Because the plants can only absorb nutrients within a specific window, an environment that is too acidic or alkaline can cause nutrient lockout. This will lead to nutrient deficiencies that may stunt the plants’ growth, stress them, or even kill them. Weak plants also become more susceptible to pests and diseases, and don’t produce high-quality buds.
To get the most out of your cannabis grow, it is vital to monitor the pH of your media, and only feed and water plants with pH-adjusted solutions. This will help to ensure that you cultivate healthy, hardy plants that will produce ample yields of premium buds.