The importance of pH in the cultivation of marijuana


Growing marijuana is a practice that requires meticulous attention to various factors, pH being one of the most crucial. The correct regulation of pH in soil for marijuana crops can absorb the nutrients necessary for proper development and high quality production. This article explores the importance of pH, methods to control it and its impact on marijuana cultivation.

Fundamentals of pH

pH is a fundamental concept in chemistry and biology that plays a crucial role in marijuana cultivation. The following is a schematic development of the concept of pH and its importance in marijuana cultivation:

Definition of pH

  • Concept of pH: pH is a measure that indicates the acidity or alkalinity of a substance. It is expressed on a logarithmic scale ranging from 0 to 14.
  • pH scale:
  1. pH 0-6.9: Acid
  2. pH 7: Neutral
  3. pH 7.1-14: Alkaline

pH scale

The pH scale is logarithmic, meaning that each pH unit represents a tenfold change in acidity or alkalinity. For example, a pH of 6 is ten times more acidic than a pH of 7, and a pH of 8 is ten times more alkaline than a pH of 7.

pH measurement

  • Digital pH meters: Electronic devices that provide accurate pH readings.
  • Test strips: Paper treated with chemical indicators that change color according to the pH of the solution.
  • Liquid test kits: Solutions that, when mixed with a sample, change color to indicate pH.

Importance of pH in marijuana crops

Nutrient absorption:

  • The pH of the soil or hydroponic solution directly affects the ability of the plants to marijuana to absorb essential nutrients such as nitrogen, phosphorus and potassium.
  • Inadequate pH can block the absorption of these nutrients, which can cause deficiencies and negatively affect plant growth and health.

Performance and quality:

  • Maintaining an optimal pH is essential to ensure that marijuana plants grow healthily and produce high quality flowers.
  • Proper pH promotes root system development, allowing plants to absorb nutrients efficiently and grow vigorously.

pH adjustment and control

  • Methods for measuring pH: Growers can use digital pH meters, test strips or liquid test kits to measure the pH of soil or nutrient solutions.
  • Techniques to adjust the pH: If the pH is too high, acidifying agents such as aluminum sulfate can be added. If it is too low, alkalizing agents such as agricultural lime can be used.
  • Commercial products: There are specific products to adjust the pH that are easy to use and are available in stores specialized in gardening and cannabis cultivation.

Common problems related to pH in marijuana crops

  • pH too high: Can cause iron, manganese and phosphorus deficiencies, resulting in yellow leaves and slow growth.
  • pH too low: Can lead to calcium, magnesium and potassium deficiencies, resulting in brown spots and twisted leaves.
  • Symptoms and solutions: Identifying symptoms and adjusting pH immediately is crucial to avoid permanent damage to plants.


The pH is a critical factor in the cultivation of marijuana which directly influences nutrient uptake and thus plant health and productivity. Whether growing indoors or outdoors, it is essential for any cannabis grower to measure and adjust the pH to ensure proper development and the production of high quality flowers.

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