The modern age of technology has allowed us to move the garden from the outdoors into carefully controlled environments where we can fine-tune every aspect of the growing process. Hydroponic technologies have allowed us to ditch traditional soil and maximize nutrient absorption, all the while saving water and producing higher yields.
Of course, hydroponic systems have come a long way since they were first envisioned. These are the six types of hydroponic systems that you will find in the modern cultivator’s growroom.
Deep Water Culture
Deep water culture (DWC) involves the suspension of the plant above a nutrient solution in which the root system is completely submerged. We all know the effects of overwatering, so how do plants in this set up survive? Since overwatering deprives the root system of oxygen, the nutrient solution in a DWC system is aerated with oxygen bubbles that flow upward from the bottom of the reservoir. This provides all the oxygen the root system needs. Injecting air through a pump and various hoses allows the grower to control the size of the bubbles and the amount of aeration.
Ebb and Flow
Ebb and flow hydroponic systems involve the use of a tray and reservoir system. The reservoir system holds water and your nutrient solution. Above it sits what is called a “flood table.” Connecting the flood table and the reservoir are two tubes. One tube is connected to a pump in the reservoir that keeps a steady flow of water cycling through the tray. The other tube is connected to an overflow, which delivers the nutrient solution back into the reservoir.
Plants growing in an ebb and flow system are potted in a neutral medium and only sit an inch or two beneath the surface of the water. This allows the root system to absorb as much as it needs while receiving proper aeration.
Nutrient Film Technique
One of the more intricate hydroponic arrangements is known as nutrient film technique (NFT). This also involves the use of a reservoir and pump system. The plants are situated in net pots that allow the root system to hang down, and these pots are aligned in a row down the center of a channel.
The channel resembles a hollow tube with a flat bottom and holes in the top for the plants. The nutrient solution is pumped up from the reservoir to the top of the channel. The channel must be positioned at an angle so that the water flows over the lower tips of the roots and back into the reservoir. The flat bottom on the channel allows for an even layer of solution to cascade over its surface, feeding the root system on the way down.
Wick systems work exactly the way you think they do. A pot is connected to a reservoir by a large wick that soaks up the nutrient solution and delivers it to the root system. As the root system absorbs the solution, more is pulled up from the reservoir below. The best media to use in a wick system are cocoa coir or perlite, as they have a high level of absorption and water retention. However, wick systems are more basic than other types of hydroponic systems and they have their drawbacks.
Unlike other mechanisms that deliver water to the root system, the wick method does not always provide enough water to completely saturate the media. So, even though wick systems are simple to use, they are best reserved for small plants or if you have limited space.
One of the more advanced techniques of hydroponics is called aeroponics. Aeroponics utilizes a net pot and hanging root system like NFT. The roots hang above the nutrient solution reservoir, but the roots and root tips are not submerged. Instead, the nutrient solution is delivered by means of a pump and misting system. These deliver precise amounts of water and nutrients at very specific times to ensure maximum absorption.
The physical design of aeroponic systems can vary, as the upper tray that holds the net pots can be shaped to fit your space. As you really can dial in on the specific needs of your plants, aeroponic systems work extremely well. They are fairly simple in design but can be expensive and tricky to put together, so they are not for a beginner to hydroponics.
A drip system is another more advanced hydroponic system. It has a reservoir system that utilizes an air pump to keep the reservoir solution moving and a nutrient pump that sends your solution up to the plants. In this case, the root system is not exposed. The plants are grown in your standard hydroponic medium like coco coir or vermiculite.
When the water is pumped up from the reservoir, it is fed to the plants through from hoses above the top layer of medium. The water literally drips from the hoses onto the medium and is controlled by a timer to go on and off at specific intervals. Set up isn’t exactly a snap, so they should probably be reserved for more advanced hydroponic gardeners.