WHAT IS THE CORRECT PH FOR CANNABIS?
A natural assumption is that sitting pretty with a pH of 7 would be ideal—many of us often see the middle ground as a safe space. Instead, cannabis plants prefer more acidic media. A slightly acidic growing medium also supports beneficial fungi.
An important side note at this point; even moving one number up or down on the scale will have a significant impact on your cannabis plants. A substance measuring a pH of 6 is ten times more acidic than a pH of 7. A pH of 5 is a hundred times higher in acidity. Smaller, menial adjustments are always the preferred method with pH, providing limited stress to your beloved weed!
To further complicate matters, depending on the grow setup you have opted for, the required pH also varies. No need to be alarmed though, we will cover both hydroponic and soil-based setups and their pH guidelines.
HYDRO
IDEAL PH: 5.5-5.7
Hydroponic growing environments can prove slightly more troublesome when it comes to effectively managing pH levels. The reservoir you apply your nutrient solution to has direct access to the root structure of your plants. Because there is no soil medium to dilute any mistakes made, less is more when it comes to increasing or decreasing pH levels.
There are simple ways to do this with additives, which we will explore later. The reason hydroponics prefer a more acidic solution to soil is that typically, water tends to have a neutral to slightly alkaline pH.
SOIL
IDEAL PH: 6.3–6.7
Soil-based grows have a slightly larger margin for error and can be more forgiving if your pH levels go awry. The most significant cause of fluctuations of pH levels in soil is a result of the breakdown of fertilizer. Acidic salts get left behind, lowering the pH of the soil.
An essential tip is to correctly mix the soil. It is not as uniform as a hydroponic setup; therefore, one patch of soil will provide a different pH compared to an area that hasn’t been mixed correctly.
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GETTING PH WRONG
No matter your experience, there will come a time when getting pH wrong happens. Knowing the signs of incorrect pH in your cannabis plants and what effect this can have are vital. Starting with the latter, what happens to your cannabis when pH is too high or too low?
The buildup of salts we mentioned earlier? Acting as a blocker, salts prevent your cannabis from being able to absorb nutrients. Trying to rectify this by adding even more nutrients won’t work. Correct pH is integral!
In a medium that is too alkaline, essential nutrients like calcium, iron, and phosphorus bind to each other. Similar to how the salt acts as a blocker, the bound nutrients cannot be absorbed by your plant’s root system either. Both of these situations cause what is commonly referred to as nutrient lockout.
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SPOTTING THE SIGNS OF INCORRECT PH
Stunted growth, wilting, and brown or yellow leaves are all signs of incorrect pH and/or nutrient deficiency in cannabis plants. However, these symptoms can also be the outcome of a different problem with your cannabis.
The best course of action is, when in doubt, take a reading of pH levels. Readings can be taken quickly and simply, helping you to diagnose any problems.
