How to Ensure the Correct pH Levels for Cannabis Plant Growth

Commercial cultivation of cannabis demands a high level of precision, and maintaining the pH level of the growing medium is one of the most crucial aspects of this process.

How to ensure the correct pH levels for cannabis plant growth

Image Credit: ARES Scientific

The acidity level, commonly known as the pH level of the growing medium, has a direct impact on the availability of nutrients to the cannabis plant, and achieving the correct pH level is essential for ensuring optimal growth and yield.

The pH level is a measure of the acidity or alkalinity of a substance, expressed on a scale ranging from 0 to 14. A neutral substance has a pH of 7, while numbers below 7 indicate acidity, and numbers above 7 indicate alkalinity. Therefore, the pH level is a useful indicator of the acid-base balance of a solution.

How to ensure the correct pH levels for cannabis plant growth

Image Credit: ARES Scientific 

How pH Affects Plant Growth

The pH of the growing medium should ideally be between 6.0 and 7.0 for cannabis plants. This range is considered neutral and allows the plant to absorb the necessary nutrients from the soil or growing medium.

When the pH level is too low, the growing medium becomes overly acidic, impeding the plant’s ability to absorb vital nutrients such as phosphorus and potassium.

Conversely, if the pH level is too high, the growing medium becomes too alkaline, making it difficult for the plant to access other important nutrients such as iron and zinc. Therefore, maintaining an appropriate pH level in the growing medium is critical to avoid nutrient deficiencies and ensure healthy plant development.

If the pH level of the soil is excessively acidic or alkaline, it can cause hindered growth, nutrient insufficiencies, and reduced yield.

The optimal pH range for cannabis plants varies slightly between the vegetative and flowering phases of their life cycle. During the vegetative stage, the ideal pH range for these plants falls between 6 and 7.

The recommended pH range facilitates the plant to assimilate all the essential nutrients, comprising nitrogen, phosphorus, and potassium. For the flowering stage, the optimal pH range slightly increases to between 6.5 and 7.5. This range ensures the proper uptake of nutrients, as well as the appropriate development of flowers.

It is important to note that various strains of cannabis may possess distinct pH requirements. Certain strains may exhibit a higher tolerance for pH levels that are either higher or lower, whereas others may necessitate more precise pH regulation

An optimal pH range is crucial for strain growth. Regular pH measurement and adjustment prevent contamination and improve reproducibility.

How to ensure the correct pH levels for cannabis plant growth

Image Credit: ARES Scientific

Testing and Adjusting the pH Level of Soil

Regularly testing and adjusting the pH of the growing medium is essential for optimal growth. pH can be measured with a test kit or meter, available online or at a local store.

To adjust pH levels, dolomite lime or agricultural lime can be added to raise pH if it is too low, while sulfur can be added to lower pH if it is too high.

Monitoring water’s pH is crucial as it can impact the pH of the growing medium and nutrient absorption. Ideally, water pH should be within the 6.0-7.0 range. Adjusting it requires adding acidic/alkaline substances cautiously to avoid harming the plants.

The pH of the water should be between 6.0 to 7.0 for most plants, including cannabis. Extreme pH levels can reduce growth and yield and cause nutrient deficiencies. Testing can be done using a pH meter or test kit.

Adjusting pH levels can be done by adding pH-lowering or pH-raising solutions to your water or soil. It is important to adjust pH levels slowly with small increments to avoid shocking the plants.

pH meters measure the acidity/alkalinity of soil and water used for cannabis cultivation and are crucial for maintaining the desired pH range essential for healthy plant growth.

A pH meter has a 0-14 scale, with 7 being neutral, below 7 being acidic, and above 7 being alkaline. Optimal cannabis growth requires 6.0-7.0 pH, so it is vital to maintain this range to avoid harming plant health and yield.

The initial step is to utilize a pH meter to obtain a soil sample from the designated growing area. Take a small quantity of soil and combine it with an equal amount of water to produce a soil suspension.

Subsequently, switch on the pH meter and insert the probe into the soil suspension. Allow the meter to provide a reading and document the pH level. It is essential to repeat this process in several areas of the growing region since the pH can fluctuate depending on the location.


Maintaining the suitable pH level of both the growing medium and water is crucial for commercial cannabis cultivation. This factor directly influences the accessibility of nutrients to the plant, and maintaining appropriate pH levels is instrumental in achieving the best possible growth and yield.

Regularly testing and fine-tuning the pH level as required is a fundamental aspect of commercial cannabis cultivation. By maintaining the correct pH level, cultivators can anticipate strong, productive plants and generate a higher yield of quality cannabis.

ARES Scientific provides top-notch pH meters and stir plates from Ohaus to ensure precise pH measurement of the soil and to promote plant health. Ohaus is a renowned manufacturer of laboratory equipment known for its dependable and superior-quality products.

The precision and ease of use of the pH meters offered by the company have been considered during the design process, making it a straightforward task to measure and adjust soil pH levels.

The selection of Ohaus pH meters ranges from fundamental handheld models to more complex options, which include built-in data logging and automatic temperature compensation features.

Apart from pH meters, the company also provides Ohaus stir plates. These instruments are useful in achieving a more accurate pH reading by mixing and stirring soil samples. The Ohaus stir plates are engineered with a robust motor and operate smoothly and quietly, thereby making them suitable for use in any laboratory setting.

Utilizing Ohaus pH meters and stir plates will ensure that the measurements of soil pH levels are precise and dependable. These instruments aid in making the necessary adjustments required to maintain the health of plants.

ARES Scientific is dedicated to offering superior equipment and service to commercial cannabis growers, and its assortment of Ohaus products will certainly fulfill these requirements.

About ARES Scientific

Since 2009 ARES Scientific has been helping the scientific community identify and implement the most innovative and sustainable products for their facilities. We are pleased to offer our clients a pre-qualified portfolio of premier manufacturing companies specialized in building the highest quality products within their particular area of expertise. Many of these companies hold the distinction of being multi-generational family-owned companies that have been in continuous operation for decades.

Today, we are proud to say that we have helped thousands of the most prestigious institutions and businesses accelerate medical breakthroughs and enhance the quality of their patient care. Our vision is to continue building long-lasting relationships with our clients and manufacturer partners and bring them together in their quest to improve the quality of life in our communities.

Sponsored Content Policy: AZO Life Sciences publishes articles and related content that may be derived from sources where we have existing commercial relationships, provided such content adds value to the core editorial ethos of AZO Life Sciences which is to educate and inform site visitors interested in medical research, science, medical devices and treatments.

Last updated: Mar 22, 2023 at 12:21 PM


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