A Crash Course in Hyrdoponic Growing

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Hydroponic growing is a form of growing plants using oxygen, a water-based system, and nutrient filled solution. This method of growing doesn’t use soil; it requires the plant to have direct access to the nutrient filled solution. Any water not consumed by the root (remember- this is water-based system) is recycled through the system for consumption at a later time. 

This isn’t necessarily new practice; however, maybe a little newer when tied to Cannabis. Hydroponics was a method of gardening/farming back in the 10th and 11th centuries by Aztecs, and goes back even further in time.

Types of Hydroponic Systems

There are many types of hydroponic systems; here are a few:

  • Aeroponics- this method means that roots are suspended in the air. Plants consume their nutrients by way of mist to roots or using a pond fogger.
  • Wicking/ Wick System- this a low-cost hydroponic method. Plants consume their nutrients by way of material (rope), a growing medium (clay/cotton/fiber), and one end of the wick material being placed inside of the nutrient filled solution.
  • Drip System- this is an easy method, using a slow feed concept for the growing medium and nutrient filled solution.
  • Deepwater Culture- this is known as the easiest method. Using this method means that the plant roots are suspended in the solution. A pump is used for oxygen to keep that plant from drowning. 
  • Nutrient Film Technique- Also known as NFT, this system uses a continuous flow of nutrient filled solution running over the roots. Using this method means that the plants are at a slight tilt so that solution flows with gravity.

Differences Between Soil Grow and Hydroponics

Hydroponic growing doesn’t allow the same terpene development as cannabis grown in soil. Terpenes develop in dry circumstances which of course is not possible using a water-based system. Flower taste (which is subjective of course), are different between hydroponics and soil. Attention to plants is needed more with hydroponics than soil. 

Growing Cannabis Using Hydroponics

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The first consideration should be your space, your resources, and the strain of cannabis that is being grown. This is the start to selecting the best hydroponic system for Cannabis growth. Other considerations to select the best system/method:

  • What do the startup funds look like?
  • Will this be a long- term practice or temporary practice?
  • How much time can be committed daily?
  • Are power outages an issue in the area?

These considerations will help determine if a traditional soil-based system is best or if a hydroponic system is best and also- the type of hydroponic system (aeroponics, deep water, drip, etc.)

Supplies/Materials Needed to Start Hydroponic Cannabis Growth

Supplies and materials will vary from hydroponic system to hydroponic system. A few things that will be needed no matter the system:

  • Because soil isn’t required, due to the plants only using the nutrients in the soil, making sure that the plants have the elements from the soil is important: potassium, phosphorous, nitrogen, sulfur, magnesium, calcium, copper, zinc, boron, molybdenum, manganese, chlorine, and iron.
  • It is important to have a Parts Per Million (PPM) meter to keep track of the elements/nutrients in the solution. Required levels will vary during the plant’s growth stages. Like humans, too much or too little will negatively impact plant health and growth.
  • In addition to the PPM meter, hydroponic growth also requires a PPM-EC meter and a PPM-TDS meter. A PPM-EC meter measures the electricity in the water, important for measuring the electrical conductivity of the water. A PPM-TDS meter measures the amount of plant food in the water.
  • A nutrient cycle is a necessary tool help feed the plant’s on schedule. The timer works by starting the pump which places the root of plants into the nutrient filled solution on schedule. 
  • Marijuana lighting is important because light for plant growth and health is important. No matter the strain, both indica and sativa require night and day cycles for growth. The best option for the plants is full spectrum LED lights. These lights enable the grower to grow from seed to bud and they use half the amount of electricity than some other lighting, and they don’t generate heat. 

Grow Room Conditions

The grow room for hydroponic growth should have a temperature of about 70-83 degrees, ventilation, and airflow. It is important for plants to have ventilation because plants need both CO2 and light for photosynthesis. Vents- exit and intake, produce CO2 rich air into the grow room and fans are necessary to prevent mold (buds being packed tightly and moisture can produce mold). 

Advantages of Hydroponic Cannabis Growth

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Hydroponic cannabis growth is said to be the best option for cannabis quality. Growing without soil is said to be better for the environment (less water used, the water that is used- is used efficiently, and the is reusable). Hydroponics is known to produce high quality cannabis without the need for outdoor conditions. 

There is no need to test soil. Soil testing is a major first step in growing Cannabis. With hydroponics- no soil is used, so, no testing needed.

There are no worms, bugs, or other animals with the use of hydroponics. This is because the plants are being grown in a sterile environment. This means, no pesticides needed. 

Hydroponic growth produces higher yields, and farmers have reported six harvests per year with this method. Hydronics is known to be the better option for medicinal cannabis/ marijuana because there is less risk of pest infestation and disease. 

There is more growing control with hydroponic systems than there is with outdoor grow. This system allows farmers to monitor the plant’s more closely. This creates better quality.

Hydroponic cannabis cultivation is great for limited space. These systems can be set up in small rooms/ closets and have many set up options due to the ability to be built according to the grow space. There is also less need for re-potting.

Hydroponic Red Flags to Look out For

Growing Cannabis using hydroponics means limited production due to space limitations. As mentioned above, having eyes close to the growth is needed. Remember, this is a water system so, one plant with one disease means that the full crop is at risk. 

Bacteria can grow in water so, close eyes again- are needed. Fungi is food for crops. It’s important to check on the plants regularly- more emphasis on time and proper cycles. 

Electricity and power outages- many farmers that grow using hydroponics have generators. Because hydroponics relies heavily on electricity (water and light timers rely on electricity), having an “in case of emergency” plan is important. Generators are a great source.

Hydroponics FAQ

A few common questions and answers about hydroponic growing:

How often should I change my nutrient solution?

There really isn’t a rule to determine how often solution should be changed. A general rule of thumb is to top your reservoir off with fresh water without any nutrient added. Try and keep a record of how much water is being added to the reservoir and once the amount of water added equals half of the reservoir capacity, it’s time to change the solution and rinse the reservoir and growing medium.

What is the temperature range for the nutrient solution?

The optimal temperature of the nutrient solution should be in the range of 65 to 75 degrees Fahrenheit.

How can I tell if my seeds are viable?

Fill a shot glass with distilled water and place your seeds in it. After 24 hours, the viable seeds should have sunk to the bottom. Those still floating are most likely not viable and will not germinate.

Can I transfer plants from soil to hydroponics?

This can be done by washing the roots of the plant (dipping in water and trying to remove as much of the soil matter as possible). Doing this carefully is important due to the delicate roots and transplant shock. When the roots are somewhat clean, go ahead and pot the plant in the hydroponic media and begin a standard watering regimen (using a touch of B-1 in the solution for a week or so to aid in the recovery from transplanting).

Time to Grow!

While hydroponics growing does require more time and attention than soil growth, cannabis plants will thrive efficiently. Hydroponics is the most environmentally loved, small space friendly, multiple harvests per year- method of growing. It has been a method of gardening and farming since the beginning of time and continues to gain popularity. 

Written by: Veronica Castillo

This piece was written by author and published originally in Oklahoma Chronic Magazine. The piece has been edited for SEO.