Updated at: 20-06-2022 - By: Sienna Lewis

Growers who learn how to test soil ph cannabis will benefit from understanding the three alternatives. The quality of your crop will much improve if you know everything there is to know about cultivating cannabis, such as how to set up a greenhouse for optimum results. Remember that other factors, like as the soil, can have an impact on your results.

As with other crops, ensuring that the soil pH is just right is critical when growing cannabis. The productivity of the soil is affected by the pH of the soil, which indicates possible plant problems. As a means of assuring optimal growth and blooming, soil pH testing for cannabis provides helpful insight into the soil’s acidity and alkalinity.

How Does pH Stop Cannabis Nutrient Deficiencies?

On a scale of 1-14, PH indicates how “acidic” or “alkaline” something is. Pure water, with a pH of roughly 7, is considered neutral. The concentration of hydrogen in the sample is a factor in pH measurements. If you’re a cannabis farmer, you can use specific pH tester drops or a digital pH pen to measure the pH of a water sample.

How to Test & Adjust Soil PH for Growing Cannabis Plants ( Seeds, Soil & Sun: Season 2 Ep 2) - YouTube

For cannabis farmers this is a critical consideration.

The roots of cannabis prefer an acidic environment. Cannabis thrives in the wild because of the slightly acidic pH of the soil. Plants can acquire the nutrients they require if their roots are at the correct pH level. Too much or too little pH in the root zone can cause cannabis deficiency since the plant can’t absorb nutrients adequately!

Having Healthy Leaves Is Easy When You Pay Attention to pH!

Some cannabis producers are unlucky and don’t have to bother about the pH of their soil. Perhaps they had the correct soil and the proper amount of water to generate the ideal pH environment for the roots of the plants. If your plant is doing well and showing no signs of nutritional deficiency, you may not need to worry about pH management.

Due to the lack of luck of many farmers, their plants are unable to thrive due to a pH imbalance in their growing environment. Despite the fact that there are techniques to avoid testing your cannabis grow’s pH, nearly all producers will benefit from doing so.

Maintaining a stable pH level…

  • with fewer issues with leaves or nutrient deficiency
  • quicker growth and higher yields can be achieved without nutrient issues in cannabis plants
  • Occasionally, producers are made aware of potential problems before they become a problem, for example, if you establish that the pH is excessively high or excessively low, you may address it before your leaves begin to suffer from shortages

Keep in mind that the roots of the cannabis plants need to be kept at the correct pH level in order to better absorb nutrients. What’s the reason for this?

Depending on the pH of the surrounding environment, nutrients can take on a variety of chemical forms. The roots can more easily take on some forms than others, but this is not always the case. Even if the nutrients are physically present at the roots, a plant can show signs of nutrient insufficiency when the pH is too high or too low.

You’re ensuring that plants have access to all of the nutrients they need at all times using pH. When it comes to growing cannabis, pH is critical for all producers, but it’s especially critical for those utilizing cannabis nutrients. Liquid nutrients are extremely available to plant roots, but only if they are designed in the correct pH range.

What Is the Optimal pH Level?

  • The pH of the soil ranges from 6.0 to 7.0.
  • Phosphorus range of 5.5-6.5 for Hydro, Soilless, and Coco

It is possible for cannabis plants to show signs of nutrient deficiency if the pH is too high or too low, even when nutrients are present in the growing media.

How pH affects Cannabis Plants (Chart) | Dutch Passion

Once you’ve mastered the art of pH maintenance, it will only take a few seconds of your time. Even after your grow has been optimized, you may no longer need to monitor the pH level.

What’s the Best pH for Growing Cannabis?

The following graphs demonstrate the plant’s ability to absorb certain nutrients at various pH levels. When you discover a certain nutrient deficit, you might use this as a goal.

Cannabis thrives in slightly acidic soil conditions in the wild. Cannabis thrives best on soil with a pH between 6.0 and 7.0, with 6.2–6.9 being the most commonly used range. Instead of always changing the pH to the same number, it’s a good idea to allow the pH cover a range.

Find out which nutrients are best absorbed at what pH levels. ‘

pH isn’t as critical in soils that don’t employ liquid nutrients. In order to avoid difficulties and provide the best harvest, it is virtually always necessary to regulate pH while applying liquid nutrients in soil.

Hydroponics, Soilless or Coco ~ 5.5 – 6.5 pH

The pH of the root zone should be between 5.5 and 6.5 in hydroponic (and soilless) growing systems (such as coco coir). Compared to the ideal soil root pH, this is a little more acidic.

Instead of always changing the pH to the same number, it’s a good idea to allow the pH cover a range.

Find out which nutrients are best absorbed at what pH levels. ‘

The pH must be allowed to vary slightly in hydroponics, as some nutrients can only be absorbed at higher or lower pHs, as can be seen above.

Make sure to monitor and adjust the pH in your hydroponic system because you’ll virtually always be using liquid or powder nutrients. You only need to fix the pH when it begins to fall outside of the 5.5-6.5 range.

What about soilless mediums like coco coir?

Because they don’t contain any nutrients, the majority of soilless growth mediums are useless to plants. Because the water is providing all of the nutrients, you don’t really need a root system. Hydroponics refers to a growing method where the plant receives all of its nutrients from the water.

However, some organic-rich soilless growing mediums may necessitate a slightly higher pH in order to survive. For example if you heavily amended your growing medium with worm castings (worm poop), you will want to aim for a pH between soil and hydroponic ranges since you’ve added “soil-like” components

No Need to Be Exact – Let pH Range Up & Down

In some cases, organic matter-rich soilless growth mediums may require a slightly higher pH level to survive. You’ll want to aim for a pH between soil and hydroponic if you heavily modify your growth medium with worm castings (worm feces), for example.

The majority of nutritional problems caused by high or low pH may be avoided if you stay to the suggested pH levels above.

Why would it be better to allow the pH to fluctuate rather than always adjust to the same number? At slightly higher pH levels, some nutrients are better absorbed; at lower pH levels, others are. It also saves a lot of time and aggravation by not having to try to find an exact number.

If you detect that the pH of your marijuana plant’s roots is off, it’s best to take action right away rather than waiting until the leaves start to show signs of stress. It can be tempting to ignore a pH problem, but you’ll often get the best results by acting before your plant displays a problem. That being said, if your plant appears to be flourishing and healthy, it may be time to let it go and let nature take its course.


Taking action as soon as you become aware that the pH of your marijuana plant’s roots has shifted is the best course of action if this occurs. A pH problem can be tempting to ignore, but you’ll get the best results if you act before your plant shows signs of trouble. On the other hand, if your plant is flourishing in a healthy state, it may be best not to mess with it.

You don’t need to be precise, but if you see that the pH is growing too high or too low, you should take action.

Before altering the pH, make sure you’ve added all of your nutrients to the water. The pH of your water will be affected by the fertilizers you add, so be sure to add these first.

How To Test Soil pH Cannabis For Beginners

Choose your method

Option #1. Soil testing facilities

You can begin by searching for licensed soil testing laboratories in your area and determining which one is the closest. The only thing you have to do is email them a sample, which may make this a more convenient alternative for you. If you plan to send soil samples, the University of Massachusetts has given a checklist.

Doing media tests or submitting a sample two hours after fertilizing in the growing season are important aspects to know and apply to cannabis cultivation. Slow-release fertilizer pellets should also be avoided while shipping soil. Then, while analyzing the data, stick to the soil testing method you’ve chosen and never compare results from different facilities because they may use different testing methodologies.

Option #2. Handheld pH meters

Using a pH meter, any gardener can perform the second way of measuring soil pH for cannabis. This method is more do-it-yourself friendly. Probes can be inserted into the soil in one of two ways, both of which are simple and require no special equipment. There are numerous advantages to learning how to operate a pH meter.

The advantages include being able to conduct tests on your greenhouse at any moment and get the findings right away. Using this method, you can swiftly make alterations to your cannabis plants, saving you both time and money. However, you should exercise caution when selecting a method to ensure that the findings you receive are accurate.

Option#3. Testing kits

Testing kits are a simple and cost-effective option for the do-it-yourselfer. A pH testing kit, on the other hand, makes use of water and a test solution. Use a color-coded chart to determine the pH of the soil after adding these two ingredients.

There are a variety of testing kits to pick from, and you may select the one that best suits your needs. It’s all about combining soil with dechlorinated water and inserting your test specimen, which is a simple notion. Take note of the color change and use the pH table to determine the concentration.

563 Soil Acidity Photos - Free & Royalty-Free Stock Photos from Dreamstime

How to adjust soil pH for cannabis

If you’re growing cannabis, you’ll generally want a soil pH of 6 to 7. When you’re outside of this range, your plants are at risk of not receiving the nutrients they require to grow and flower. While maintaining a pH between 6 and 7 is simple, if your soil turns out to be excessively acidic or alkaline, you’ll need to know how to change the pH.

Take note if the pH of your soil is 5 below or 7 and above once you have tested it. Soil with a pH of 5 or lower is acidic, while soil with a pH of 7 or above is alkaline. Either way, they’re outside of the range that’s thought to be optimal for both health and efficiency.

How to make the soil more acidic

If you want to lower the pH of your soil, you’ll have to increase the acidity of your soil. Use an acidifier to raise the soil’s sulfur level. Calculate the amount of acidifier your soil will require to achieve the desired pH balance.

How to make the soil more alkaline

Instead, if the pH is too low, it is necessary to raise it and increase the alkalinity of the soil. Lime can be used to determine how much you’ll need based on the direction of the lime and the soil adjustments that are necessary. You can also use acid or base to alter the pH of the soil, depending on your level of expertise, in order to influence the soil’s acidity or alkalinity.

Importance Of Soil pH For Cannabis

Because of its impact on plant growth and flowering, soil pH is an important consideration for all producers. There is a correlation between pH and the plant’s ability to absorb nutrients and grow. As a result of having a pH range that isn’t appropriate for cannabis, other nutrients can be locked out and become deficient.

In addition to soil pH, beneficial bacteria in the soil play a function. Soil microorganisms break down fertilizer, which enriches the soil, and this process is made easier if the soil microbes are in the optimal pH range for this activity.


Learning and applying the plants’ ideal requirements requires a lot of time and effort if you want to succeed at growing cannabis. To make certain that your plants are getting the nutrients they need and that the soil bacteria are doing their jobs, you’ll need to learn how to conduct soil ph cannabis tests. Testing facilities, pH meters, and testing kits are all possibilities for soil pH testing.