An Introduction to Hydroponics

One way to grow crops that I've found to be very interesting is hydroponics. When growing things hydroponically, you're just growing without soil - instead, you use some kind of alternative media to suspend the roots and add nutrients directly to the water.

A few examples of these alternative media could be hemp mats, foam collars, rockwool, or clay pebbles. You have plenty of options to choose from, and there are also various types of systems you could build depending on your preferences and requirements.

Let's take a look at some of the different types of systems.

Wick

When it comes to hydroponics, a wick system is the simplest. You have a water reservoir situated below the plants and wicks that have one end in the water and the other in the growing medium. The wicks absorb water and transfer it to the roots of the plant. Each plant should have at least one wick dedicated to it.

Deep Water Culture (DWC)

With a deep water culture system, the roots of the plants remain submerged in water 24 / 7. Many times, you'll have some kind of net pot with a foam collar or clay pebbles supporting the plant structure, and the roots will remain in water as they grow. To provide oxygen, you can utilize an air pump and air stone or, if you're working with a small system, as the plant grows and absorbs water, the water level will lower, providing additional oxygen to the roots.

Nutrient Film Technique (NFT)

NFT systems are designed in such a way that the plants are all placed in a tube or trough that sits on a slight angle. You have a pump that moves water from a reservoir to the highest point of the trough, which then flows downward and drains back into the reservoir. Plants will absorb the water and nutrients through their roots as the water flows back into the reservoir.

Ebb & Flow

Ebb and Flow is similar to an NFT system in that a pump will push water into the area where plants are situated. Rather than water flowing back right away, the container holding the plants will "flood" and only starts to drain once the water level overtakes the height of the overflow drain. Many times a timer will be setup to turn the pump on and off, so the grow tray floods at regular intervals.

Drip Irrigation

When using drip irrigation, you have a pump that pushes water though tubing and out of drip emitters that are situated directly above, or near the base of the plants. When designing the system, you can choose the flow of the drip emitters - for example there are some that allow 1 gallon per minute, or 2 gallons per minute.

Aeroponics

Aeroponics is the most complicated of the systems. You still have a reservoir like the others, but rather than having water flow through a trough or drip on the plants, the roots are exposed to air and misters are situated under them. Periodically, a pump will push water through the misters with high pressure that minimizes the water droplet size to increase water an nutrient uptake by the roots.