So, you want to grow your own cannabis. In this article we will discuss different growing techniques, nutrient systems, and optimal pH levels.
Growing Techniques: Soil-based and Hydroponics
The usage of soil-based mediums to grow cannabis is the most traditional and newbie-friendly of available techniques. Soil is composed of three elements: clay, sand, and silt. Cannabis requires properly irrigated and slightly acidic soil.
Each soil type has its own pros and cons. Of the three soil components,silty soil is arguably the best due to its high moisture content and porous nature. Although sand is very malleable,it doesn’t hold as much moisture in comparison to silt. Other binding agents such as peat moss or compost will be needed.
Hydroponic or soilless mediums are popular amongst indoor growers. This is primarily due to the fact that hydroponically-grown cannabis can lead to larger, faster yields. Liquid mineral nutrients replace the role of soil and the aqueous nutrient solution is absorbed directly by the plant’s roots. Because buffering organic media isn’t used, hydroponic growers must exercise more precision to ensure the root’s environment is appropriate.
To better ensure a healthy and prolific harvest, it is essential that your cannabis is given the proper nutrients. Nutrients can be provided in a number of ways ranging from pre-fertilized soil mixes to specifically-crafted nutrient solutions.
Nitrogen, phosphorous, and potassium (NPK) are the three essential macronutrients that cannabis plants use during the growing process. Do proceed with caution, however, as cannabis is rather sensitive and can be damaged if overfed. In a smaller scale, it is recommended that cannabis plants receive calcium, magnesium, iron, and copper.
Maintaining a healthy soil pH range is an essential part of the growing process. The pH of the soil determines which nutrients will be soluble, and thus, also controls the growth and health of the plant through metabolism and nutrient uptake.  Since cannabis requires a slightly acidic growing medium, a soil pH range of 5.8 to 6.5 is suggested, with an optimum water pH between 6.0 and 6.3. 
Hydroponic systems require a different range of pH levels, typically between 5.2-5.8.  Due to the fact that hydroponic growing methods are often solution based, pH levels above 6.5 can lead to the condensation of micro-nutrients from the solution mix. It is perfectly normal to have pH levels drift during the growing process. Your growing method of choice will range on a variety of factors, such as whether you’ll plant indoors, outdoors, hydroponic, aquaponic, general level of experience, etc.
References: Rosenthal, E. Ed Rosenthal’s Marijuana Grower’s Handbook, Quick American Publishing, Oakland, CA, 2010.  “Recommended methods for the identification and analysis of cannabis and cannabis products.” UNODC, 2009.
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