In this Hydroponics Beginners Guide, we will explore what is Hydroponics and what are some of the most common form of Hydroponics systems and their uses
Hydroponics is the practice of growing plants without the use of soil. This is done by delivering nutrients to the plant roots through a nutrient solution. Hydroponics is often assumed as a new farming technique, however its origins can be traced back to ancient civilizations, it is believed that the Hanging Gardens of Babylon used a similar method to grow food. NASA has extensively researched and adopted hydroponics in the space program. In recent years, Hydroponics has taken off in both urban environments (where access to year-round cultivable-land is rather limited) and commercial farming, as it provides a lot of benefits.
Different Hydroponic Systems
There are many different hydroponic systems: Wick, Deep Water, Ebb and Flow, Drip irrigation, Nutrient Film Technique and Aeroponics. These systems can be classified as:
- Active (Deep Water, Ebb and Flow, Drip irrigation, Nutrient Film Technique and Aeroponics) which requires moving parts i.e. an electric pump to circulate the nutrients
- Passive (Wick) which uses the natural capillary system to deliver nutrients to the plant. Different plants grow better in certain hydroponic systems.
Hydroponics Wick System
This is a very simple passive system, meaning they have no moving parts. The plant is placed in a net pot with peat or other medium, on top of a capillary pad that wicks water up from a reservoir to keep the plant roots moist. Wick system is easier and cheaper to maintain than active systems such as Ebb and Flow, but they also have the drawback of being less efficient and not well equipped for large plants that consume a lot of water. Herbs such as rosemary that don’t require a lot of water are the best choices for this system, while thirsty plants such as tomatoes would not do well.
Hydroponics Deep Water System
The deep water system also know an as floating raft system is the most commonly used active Hydroponics system. In deep water system, plants are grown in a container that holds the nutrient solution. The plants are suspended in the nutrient solution using a net pot, which is attached to the lid of the container. Alternatively one can use a floating Styrofoam raft that can host the plants. Deep water system is an active system and uses an air pump to aerate the nutrient solution. This process of aeration increases the dissolved oxygen in the nutrient solution, thereby promoting plant growth. This a very good hydroponic system for a beginner as it has very few moving parts and is very easy to build and maintain.
You can grow almost any lightweight crop in this system. Lettuce and other leafy greens are the easiest and most straightforward, and their short growing time makes them ideal for a beginner project. Herbs are also an excellent choice — parsley, chives, and basil grow easily as well. Some other lightweight options include Watercress, Cabbage, Chilli Peppers and Bok Choy. Even though hydroponics systems are most often used to grow foods, you could also plant a small indoor flower garden using this method.
Hydroponics Ebb and Flow System
Sometimes also called Flood and Drain, is also another popular system with urban backyard hydroponics. It consists of plant tray, reservoir, and submersible pump with timer. The reservoir is placed at the bottom with the plant tray above it. A timer is used to set the submersible pump, to fill the plant tray full of nutrient water from the reservoir below, which flows up through the bottom of the net pots, to the roots of the plants. The water is then drained back out, allowing the roots to become completely dry and oxygenated before flooding again. Because of the constant movement of water, it is important that you thoroughly scrub, clean and sterilize your growing medium, reservoir, pots, and plant tray in between seasons. Ebb and Flow systems can seem daunting to beginners, but they are perfect for the hobbyist with a bit of experience who is looking to “upgrade” their system. This is a very useful system, especially when you want to grow a lot of plants in rows, one above the other. It is also very popular to grow tomatoes and beans in these systems because trellises can be attached directly to the plant tray’s stand.
Hydroponics Nutrient Film Technique
This one is similar to Ebb and Flow, in that the system uses a pump to deliver nutrient water to the grow tray and a drain pipe to recycle the unused nutrient solution. The difference is that in NFT, the nutrient solution is continuously flowing over the roots. This is accomplished using gravity. The nutrient solution flows in a thin film over the roots, ensuring that they are watered and fed but not completely soaked. The thin film ensures that the upper part of the roots will remain dry and have access to oxygen in the air.
Nutrient Film Technique uses tubes or channels instead of flat trays for the grow tray. This makes it easier to set it at an angle and to make sure that the nutrient solution flows directly to the roots without wasting any of it. Most often in DIY systems, a round tube or PVC pipe is used, with holes drilled to fit the net pots and seedlings. This has the advantage of being cheap and readily available to the home hobbyist.
The main disadvantage to using PVC as your grow tray is that the film will not evenly coat the rots. The roots in the middle would have access to a deeper depth of solution, while those closest to the edges would only have a shallow depth. This can cause uneven growth and weakness in your plants. By using a flat-bottomed channel, this problem is eliminated. Channels can also be easily built at home using simple materials such as 2×4”s and water-proof plastic lining.
Nutrient Film Technique works best if you choose plants that do not require a lot of support- light weight, fast growing plants that can be harvested quickly. If you want to grow plants such as tomatoes or squash, just make sure that you have proper support systems in place such as trellises. The roots are not suspended in a growing medium in this system, so they cannot handle supporting a lot of weight from a top-heavy plant.
Hydroponics Drip System
Drip Irrigation system is a great water-saving solution and ideal for large-scale industrial farms that want to save money and resources. Drip irrigation allows for the controlled release of just enough nutrient solution to nourish the roots without any waste. Systems with large surface areas of water – Ebb and Flow, or Nutrient Film systems that use open channels, are vulnerable to evaporation. Drip systems allow water to be immediately soaked in, minimizing exposure to air. In simple terms the nutrient solution is pumped out of the reservoir by a main line, usually 1 inch, which is divided into ½ inch lateral lines that run directly alongside the plants. These lateral lines contain a dripper (emitter) for each plant, which is placed directly at the plant base and provides a controlled flow of water directly to the roots. Automated drip systems are also used to regulate nutrient flow based on the type of crop being grown.
Hydroponic Systems Comparison Chart
Advantages of Hydroponics
- No need for huge farming land as it allows the crops to be produced in greenhouses, even in the desert sands. It is a stable technology for growth of plants and ensures high yields
- Water stays in the system thus labor for watering of plants can be avoided
- Lower water costs as water is reused in these systems
- Less water is lost through evaporation and runoff
- No mulching, tilling, changing of soil and weeding
- No scope of pesticide damage
- Proper aeration of nutrient solution is possible. Nutrition pollution is not released into the environment
- Easier to get rid of pests and diseases
- Easy to harvest
Disadvantages of Hydroponics
- Limited production in comparison to field conditions
- Initial setup cost is high, as the necessary equipments are expensive
- Technical skill is required to maintain the equipments
- Hydroponic gardens are affected by power cut
- If a disease appears all plants in the container will be affected. Water borne diseases can quickly spread right through the hydroponic gardens