Hydroponics and Marijuana

When it comes to growing cannabis, hydroponics is an attractive option for growing high-quality buds. A hydroponics setup tends to produce plants quickly (relative to traditional growing methods) and can be used in just about any sized space. Additionally, utilizing hydroponics in cannabis production allows growers to precisely control the nutrients the plants are receiving; this, in turn, can result in bigger, healthier, and more potent buds. A higher value, some might say.

Enclosed marijuana hydroponics garden
Photo from Wikimedia Commons

Setting Up Your Hydroponic System

A quick Google or YouTube search will produce plenty of info on how to set up a hydroponics growing system. Here are just a few tips for setting up your hydroponics cannabis garden:

Sterilize Your Equipment

This isn’t a huge concern if you’re using brand new equipment; however, if your equipment is second hand or has been used before, taking time to sterilize it can prevent the growth of pathogens that can destroy your marijuana.

  1. Watch Your Water!

Water is what carries those precious nutrients to your cannabis plants. Closely monitoring your process water will help you achieve maximum yield. Two key measurements to look at are pH and Electrical Conductivity (EC). Measurements for pH and EC as well as temperature should be taken at least two times daily.

Fresh water used for hydroponics

pH Levels

As mentioned earlier, a pH level between 5.5 and 7 is ideal for growing cannabis; this provides a good environment for the roots to absorb nutrients. pH is measured using litmus strips or a pH meter.


An EC reading measures how strong a solution is (how mineral-rich water is). An EC measurement between 0.8 and 2.0 is appropriate for cannabis plants. EC is measured using an EC probe.


A water temp of about 65 F/ 18 C provides good nutrient absorption and prevents algae growth.

  1. Don’t be afraid to use support
marijuana plants supported by a trellis system

Marijuana grown via hydroponics may not have as much support as plants grown in soil and could be prone to breaking. A simple solution is trellising; trellising plants provides support and helps plants to grow a certain direction.

  1. Know Your Nutrients

All plants, including marijuana, have very specific nutrient requirements. Familiarizing yourself with them will help you stay on top of things as you work to provide your plants with an optimal nutrient solution.


The primary, or “macro”-nutrient requirements for plants are: Nitrogen (N), Potassium (K), and Phosphorus (P)


Additionally, plants require secondary, or “micro”-nutrients. These include Boron, Calcium, Copper, Iron, Magnesium, Sulfur, and Zinc .

Nutrient Solutions for Hydroponics

Nutrient solutions come in either a premixed or powder form, and provide the necessary macro and micronutrients. Premixed options are a bit more fail-safe, but with can be successfully used to grow cannabis plants hydroponically. There are many options used to deliver nutrients to the plants in the most effective way, including using clay pellets and the nutrient film technique (NFT), or the film technique. The idea of nutrient film distributes dissolved nutrients through a shallow stream of water directly to the roots of the plants. Special clay pellets help with the oxygenation of the water, improving nutrient absorption. Although these methods are often used for faster growing crops, using clay pellets and the nutrient film technique are great examples of the various ways you can optimize your hydroponic growing setup. 

  1. Light it Up!

The right grow light fixture for your hydroponics setup depends on space, distance between light and plants, and your budget. Whatever you decide to use, the fixture should produce light in amounts between 400- 700 nanometers (an inexpensive light meter can help you measure this).

A hydroponics garden with lights

Hydroponics grow lights typically use one of the following types of bulbs:

  • High Intensity Discharge Lights (HID)-This lighting is better for larger grow rooms with good ventilation.
  • Compact Fluorescent Lights (CFLs)– These are fairly inexpensive and good for smaller rooms.
  • Light Emitting Diode (LED)- LEDs are good for small areas but more expensive than CFLS
  1. Monitor Humidity and Air Flow

Humidity requirements vary for cannabis depending on the stage of growth. Young plants need 60-70%. Plants in the blooming phase require humidity levels of about 40%. Humidity levels can be adjusted using either a humidifier or dehumidifier as needed.

Maintaining proper ventilation and air flow aids in temperature distribution. Air temps should be kept at around 75 F.

Careful Process Temperature Control

As mentioned earlier, when growing marijuana hydroponically, it is best to keep the water temperature at around 65 F and the air temperature at around 75 F. These ideal temperatures will help cannabis plants absorb maximum nutrients. In especially warm climates, a process cooling solution may be required.

Fluxwrap tank jacket

Fluxwrap from AG Optimists keeping a reservoir at a Marijuana farm cool

AG Optimists’ process chillers and extraction chillers take up minimal space within your current hydroponics cannabis setup, are almost effortless to install, and are made to order– that means your cooling solution can be custom tailored to fit the needs of you operation. If you’d like more info on what cooling solutions are available for your hydroponics setup, give us a ring at 541-610-6858 or shoot us an email at


A Crash Course on High-Quality CBD Extraction

Increased research on the potential benefits of cannabidiols (CBD and THC) extracted from cannabis plants has led to growing popularity in CBD and THC oils. These high-value extracts require careful extraction methods to go from cannabis plant to oil. Here are a few of the most common CBD and THC extraction methods.

CBD vs. THC- What’s the Difference?

THC and CBD are the two main cannabinoids extracted from cannabis plants. Marijuana has a higher percentage of THC while hemp has a higher percentage of CBD. Put simply, THC has the psychoactive properties associated with getting “high” while CBD is said to have more calming, medicinal properties.

Common Extraction Methods

Solvent Extraction

This simple extraction method works by using ethanol as a solvent to remove extracts from cannabis plant trimmings. It usually looks something like this:

  1. Ethanol is added to trimmings and mixed for a couple of minutes to allow the ethanol to dissolve extracts from the plant materials.
  2. The ethanol is strained from the trimmings.
  3. The ethanol/extract mixture is slowly heated until all ethanol evaporates and only the plant extracts remain.

Solvent Extraction Pros:

  • Inexpensive- This method doesn’t require any fancy machinery.
  • Simple- This method is pretty straightforward and can even be done at home.

Solvent Extraction Cons:

  • Dangerous- Ethanol is extremely flammable.
  • Could Damage CBD/ THC- Ethanol could potentially denature the CBD or THC if overheated or overmixed.

CO2 Extraction

The COExtraction method uses supercritical carbon dioxide to pull phytochemicals from cannabis plants. Supercritical materials are not quite a liquid but not quite a gas and possess the properties of both. This state is ideal for plant extraction because supercritical COcan move through materials like gas and dissolve materials like a liquid.

CO2  extraction typically follows these steps:

  1. The COis prepared in a compression chamber. First, CO gas is turned into a liquid; this is done by dropping the temperature to under -69°F and increasing the pressure to over 75 psi. Next, the the temperature and pressure are both raised until the liquid becomes supercritical.
  2. The supercritical COpasses through cannabis trimmings in an extraction chamber where it dissolves and collects extracts from the plants.
  3. The CO/ extract solution then enters a lower-pressure separator chamber. The lower pressure causes the CO2  and plant extracts to separate. The COreturns to the COchamber and the cannabis oil is drained from the separator.

CO2  Extraction Pros:

  • Safe when done by professionals- CO2 is used in countless food products and is perfectly safe for consumption
  • Yields high-quality CBD- machines leave very little room for error

CO2  Extraction Cons:

  • Very expensive- setup costs start at approximately $40,000
  • Not for novice chemists- it’s best to leave this method to the professionals

Ice Water Extraction

Ice water extraction creates a powdery resin extract often referred to as “hash” or “bubble hash.” There are several variations to this method, but they all follow these general steps:

  1. Finely-chopped plant trimmings are mixed with either ice or dry ice.  This step is supposed to help separate extracts from the plant material.
  2. Water is added to the ice and trimmings and the entire mixture is strained through a mesh bag. (Often, the mixture is strained multiple times through progressively smaller-micron mesh bags until the purest-possible extracts are obtained)
  3. The extracts settle at  the bottom of the strained mixture. The excess water is drained from the top and the extracts are left to dry until they become powdery.

Ice Water Extraction Pros:

  • Inexpensive- Again, no fancy machinery needed!
  • High Yield- If done correctly, this method produces a relatively large amount of plant extract.

Ice Water Extraction Cons:

  • Not always practical- This method can be labor intensive and time consuming.

Temperature Control During Extraction

Regardless of the method used, careful temperature is control is an important element of high-quality yield in CBD and THC extraction. Extreme temperatures damage cannabinoids. Additionally, many processes need specific, extreme temperatures to be effective; if ideal temperatures are not maintained, the extraction process could completely flop. AG Optimists’ extraction chillers offer precise temperature control at sub-zero temperatures. Give us a call at
541-610-6858 and we’d be happy to tell you more about our products.