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What Makes Up A Hydroponic System?

Every hydroponic system is made up of components. Each of these components provides an important function for the system to work correctly and provides your cannabis plants with optimal conditions.

     

Growing Chamber or Tray

This is simply the part of any hydroponic setup through which plant roots will be growing. The perforated chamber allows the roots of the plant to be submerged in the reservoir containing the nutrient solution dissolved in water so that the roots have proper access to the dissolved minerals.

The growing chamber or tray protects the cannabis plant from external factors such as light, heat and pests. Your plant needs to be protected from the fluctuations in light and temperature as any changes from the optimal environmental conditions can cause stress in plants which ultimately hinders the proper growth and yield. The nutrient solution temperature is also an important factor for keeping the root zone comfortable for your growing plant. 

Growing chambers or trays come in various shapes and sizes and will entirely depend on the type of hydroponic system you choose.

   

Reservoir

This is the base of any hydroponic system and holds the nutrient solution. This nutrient solution is a mixture of water and plant nutrients. Depending on the type of system, the nutrient solution is either pumped up from the reservoir up to the growing tray or chamber in cycles frequently or the roots are emerged down into the reservoir permanently, making the reservoir a growing chamber as well.

The reservoir should always be light proof. This is because light promotes fungal growth, algae and microorganisms to start growing. Even low light levels can be harmful to growing plants. You can check to make it is light proof by holding it just over your head and see if any light comes through. Some growers will either paint the container or cover it with something like plastic sheet insulation if the container is not completely light proof.

 

Water Pumps

Almost every hydroponic system requires a submersible pump to pump the nutrient rich solution from the reservoir into the growing tray for the plants roots to absorb. 

There are two types of water pumps:

 

Inline Pumps - An inline pump sits outside of the reservoir. Because of this, they are usually cooled by the air and will be noisier than submersible pumps. These pumps are generally more powerful and used in commercial or larger grows.

 

Submersible Pumps - A submersible pump sits inside your reservoir with the water acting as noise insulation. While the water cools the pump, it does not mean heat will seep into your mixture. You will need to ensure this does not warm your mixture up too much. These pumps may lack the power of inline pumps but are perfect for home growers.

 

Air Pumps and Air Stones

Just like humans, plants need oxygen to survive. In a hydroponics system, water is used to grow the plants. If the plants roots are fully submerged in water with no oxygen, they can quickly drown and could die. Therefore, it is so important to provide them with oxygen. There are two ways that you can provide oxygen to your cannabis plants; Air pumps and air stones. 

Air diffuses into water whenever the two come into contact. This commonly occurs when water on the surface of the reservoir touches the air in a grow room or when air bubbles rise through a column of water in a reservoir. Many growers use a combination of an air pump and an air stone to add oxygen to their nutrient solution.  This is an efficient option for many growers and is one that can increase dissolved oxygen levels inexpensively.

The function of an air pump is simple yet essential. The air pump supplies air and oxygen to the water and then to the roots of your growing plants. An air pump pumps air through food grade plastic tubing to the bottom of the reservoir, where it is attached to an air stone. The air stone then diffuses the air into small bubbles which rise through the water, increasing the dissolved oxygen level as they rise. The rule of thumb is that a system with fully submerged roots needs an air pump. 

By using an air pump, you can take advantage of the diffusion of air into water. When placed at the bottom of your reservoir and combining it with a high quality air stone, the bubbles produced will increase the dissolved oxygen levels in your nutrient reservoir as well as the added bonus of keeping your reservoir evenly mixed, preventing the fertilizer from settling to the bottom of the reservoir. The circulating oxygenated water also helps reduce pathogens from developing in the reservoir.

 

What is Dissolved Oxygen and Why is it Important?

Molecular oxygen, more commonly known to home growers as dissolved oxygen, is the oxygen used by aquatic creatures and the aerobic organisms living in and around a plant's rhizosphere. 

When it comes to aquatic life applications, water quality is based on its dissolved oxygen content. The more dissolved oxygen, the better the water quality. This standard should be applied to water used for plants, especially plants growing in hydroponic systems.

Good quality water that has a high content of dissolved oxygen is essential to a successful indoor cannabis grow. If there is not sufficient dissolved oxygen in the nutrient solution the feeder roots will suffocate and die. This makes it difficult for the plant to stay healthy if the nutrient solution is continually depleted of dissolved oxygen.

 

Factors that Affect Dissolved Oxygen

There are two major factors that affect dissolved oxygen content: temperature and salinity. Salinity is not as critical as temperature because by the time a medium or nutrient solution's salinity level is high enough to affect the content of dissolved oxygen, the chances are good that the plant would have already been showing signs of over-fertilisation or toxic salinity.

Temperature, however, is the most crucial and controllable factor related to dissolved oxygen. Temperature affects the solubility of oxygen in water, as the temperature gets warmer the dissolved oxygen decreases and as the water temperatures get cooler, the potential dissolved oxygen content increases. This means that if the temperatures in your grow room rise, the dissolved oxygen in your hydroponic system can rapidly decrease as a result. 

This is why it is so important to control the temperature of your nutrient solution.

 

Temperature Control for Water

The ideal hydroponic temperature range is somewhere between 18 °C and 20 °C for optimal plant growth.

The first way to control the temperature of your water is to control the temperature of the grow room itself. Hydroponic systems, reservoirs, and anything else in the grow room will eventually take on the ambient temperature of the room. 

Once the water in your hydroponic system gets hot, the dissolved oxygen content will decline low enough that beneficial aerobic organisms will die off and pathogenic anaerobic organisms will find favourable conditions to thrive and harm your plants.

There are a few ways you as an indoor grower can effectively control the ambient temperature such as implementing air conditioners, exhaust and intake fans and air-cooled reflectors for grow lights.

There are also a few ways in which you can control the temperature of your water solution. The two most popular being water chillers and aerating your plant's root zone.

 

Water Chillers

A Water chiller is essentially an air conditioner for water. They can be used if your hydroponic system is susceptible to heat from the environment or if you are using large submersible pumps that give off heat. 

Optimal ambient temperatures for CO2 enrichment are higher than normal ambient temperatures, so water chillers allow growers to maintain cool temperatures in their hydroponic systems while increasing the room temperature to maximize CO2 absorption.

Water chillers also help to battle the unwanted heat created by the large submersible pumps used in some hydroponic systems.

 

Aeration of a Plant's Root Zone

Aeration is how a grower will replace the dissolved oxygen that is naturally used up during a plant's growth process.

Aerating a nutrient solution is done by vigorous circulation or by an air pump connected to an air stone or diffuser to help replace used dissolved oxygen. As the water bubbles up or circulates, it comes into contact with the surrounding air, which allows it to absorb some of the oxygen from the atmosphere.

 

Some Final Notes on Hydroponic Components

As you can see, each component that makes up the hydroponic system is important and plays a vital role in creating the perfect environment for your cannabis plant to grow and thrive in. When running your system, always make sure you are providing your plants with enough oxygen and optimal water temperature so that you can avoid any potential problems and maintain the optimal conditions for your plant to reach their full potential.

 

Happy Growing!