Hydroponics is a type of gardening in which soil is not used; instead, a different material supports the plant’s roots, allowing it to grow directly in water.
There are multiple approaches to hydroponics, and in this article we will discuss each one’s advantages and disadvantages.
If you are thinking of adopting a hydroponics system for your home garden, keep reading to learn more.
What are the different types of hydroponics?
Although aeroponics may sound like the most futuristic of all hydroponic methods, it has actually been around for some time.
This method came about in an attempt to figure out a way to effectively aerate a plant’s roots.
In this technique, pipes are used to send a pressurized nutrient solution to the plants. When the nutrient solution passes through the nozzles, it is sprayed in droplet form onto the plant’s roots. This allows the roots to receive nutrients and water while still being able to breathe.
You can buy an aeroponics kit ready for set-up, but if you want to build one yourself, you will need a reservoir, a pressure water pump, a timer to help you set the irrigation cycles, hoses and pipes with sprayers or nozzles, and an aeroponics chamber.
An aeroponics chamber can be made from any waterproof and rot-resistant material, but it is most often made of plastic. Iron may not be a good choice because it gets too hot in the summer and too cold in the winter. Choose a matte material and avoid translucent ones because they promote algae growth.
With this method, you irrigate for very short periods, but frequently. The time of each irrigation cycle will depend on the climate and the type of plant you are growing.
The pressure system you use will also be a factor in the duration of irrigation cycles. If you have a high pressure system, or HPA, a cycle can be as short as five seconds, at five minute intervals.
When choosing your water pump, you need to consider the capacity of the pump as well as its pressure power.
Do not use a growing medium when using aeroponics. Since you are spraying the roots directly, having a growing medium in the way of the nozzles would not make sense.
The advantages of aeroponics include reduced use of nutrient solution, less water use, and great aeration. This system can be built in many ways, making it very feasible for vertical gardens. It gives higher yields than other hydroponic methods and can be used on a variety of plants. The nutrient solution can also be recycled.
The downsides of aeroponics include the challenge of keeping the climate conditions stable inside the aeroponics chamber. Doing this in a greenhouse may be easier, but doing so in small chambers is tricky. This is because air changes temperatures faster than water does, while also not being able to hold humidity very well. This is also why this system will not do well in outdoor gardens. This method is also more expensive to set up and maintain than other hydroponic methods, and consumes more electricity because the pump is constantly at work.
The aeroponics chamber consumes a lot of space in a low garden, which is why it is more convenient to do this vertically.
In short, aeroponics is great in that it uses fewer nutrients and less water while providing a high yield, but it can only truly work indoors or in a greenhouse, and also uses a lot of electricity.
2. Drip system
The drip method of hydroponics does a great job in addressing aeration. It effectively waters and provides the plant with nutrition, using hoses and pipes as the delivery system.
Drip hydroponics is very similar to drip irrigation, where hoses and pipes are used to irrigate crops, thus preventing evaporation and lowering watering costs.
The hoses and pipes procure the nutrient solution from a reservoir before sending nutrient-rich water to each plant. The water is sprinkled or dripped onto the growing medium, which will release it to the roots slowly.
If you want to build your own drip system, you will need a reservoir where you will mix the nutrient solution, hoses and pipes, a water pump to attach to the hoses and pipes, a growing medium, an air pump and a timer.
Choose your growing medium wisely, because it can affect how frequently you will need to irrigate your plants. How long the medium can hold onto the nutrients is also something to consider.
You can opt for continuous irrigation and drip moderate quantities of nutrient solution onto the plants uninterrupted for long cycles. If you are using clay as a growing medium, for example, continuous irrigation is recommended. A medium like rock wool will only need irrigation every three to five hours.
The drip system is suitable for a lot of fruit trees and a large variety of crops. It provides close-to-perfect aeration while giving you full control over how much nutrient solution you give the plants. It also uses low quantities of nutrient solution and can be used for vertical gardens. You can modify the shape of the setup to fit into odd spaces and corners of your home garden.
This system ensures that the roots of the plants do not stand in stagnant water, which lowers the risk of bacterial infection and rot, and because each plant is irrigated individually, it prevents the spread of infection.
Disadvantages of the drip system include the possibility of leakage due to the number of hoses and pipes required. Because the pump is quiet, you might not realize if it has stopped working, and your plants may go for days without nutrient solution.
The drip system is inexpensive, easy to manage and flexible. It gives you full control over the irrigation of each plant, while providing great aeration.
3. Nutrient film technique
This method is called the nutrient film technique because you are providing a thin layer of nutrient solution at the bottom of a tank. The lower parts of the roots will receive water and nutrition, while the upper parts of the roots will be able to breathe.
Researchers observed that plants grew their roots out long enough to reach the nutrient film at the bottom of the tank, and then proceeded to spread horizontally.
A nutrient film technique setup includes a grow tank that is slightly inclined, a reservoir to provide the nutrient solution and recycle it after irrigation, a water pump to bring the nutrients to the grow tank, and an air pump and pipe to carry the water to the grow tank and back to the reservoir.
The only tricky aspect of this technique is keeping the tank inclined. The ideal inclination is 1:100, or one inch of inclination for every 100 inches of tank length.
Most gardeners who use hydroponics do not use a growing medium when using the nutrient film technique. The medium may obstruct the flow of nutrient solution, and this setup does not need the aeration provided by a growing medium because a large part of the roots is already in the air.
You will not need to keep feeding or watering the roots, because the nutrient film is continuous.
The great thing about this technique is that it uses minimal nutrient mix and water, because the nutrient solution is recycled. Because of this, you can size down your reservoir.
The absence of a growing medium allows you to inspect the plant’s roots easily; you can just take them out of the grow tank and not have to remove any growing medium. This also means you can spot and treat root problems faster.
Some drawbacks of this method are the inability to use it for larger crops, since there is no growing medium to support the roots. Also, once the roots of the plant become too large and thick, the flow of the nutrient film may stop.
This technique will not work for turnips or carrots and the like, because the tuberous roots of these plants are big, while the roots at the bottom are small and will be unable to feed the rest of the plant.
Furthermore, if you do not pay close attention and the system stops, your plants will not receive nutrition and water, and your crop will be ruined.
In summary, the nutrient film technique ensures that your plants are well-aerated and allows you to be constantly aware of the roots’ health, but it does have disadvantages and limitations that can be hard to overlook.
4. Ebb and flow technique
With the ebb and flow technique, the roots are irrigated regularly for short periods. The roots will be able to breathe and dry up completely, because they will not be continuously in the water.
If you want to try the ebb and flow technique, you will need a grow tank, a reservoir, a reversible water pump to send water in two directions, an air pump to help aerate the solution, pipes, and a timer so that you do not need to keep switching the pump on and off.
You can use a growing medium with this technique, but it is also completely doable without one.
You will use the reservoir to mix in the ingredients, and then the timer will tell the pump when to send the nutrient solution into the grow tank and when to drain the grow tank. Because the tank drains out, the roots are able to dry out for some time and become aerated. Usually, the timer is set up to allow around 12 minutes per irrigation phase, every two hours.
Irrigation cycles will need to be switched off when there is no daylight or when grow lights have been switched off. Plants do not need as much water or nutrients when they are unable to photosynthesize. Thus, on average, there are around 12 cycles every day.
While the system is normally shut off overnight, you may need to keep it on when the weather or climate is dry and hot.
If you are using a growing medium, the nutrient solution distributes much more slowly and irritation is less likely to occur. However, you may need to lengthen the irrigation cycle by a minute so that the growing medium is properly soaked with the solution.
Great aeration may be the best advantage provided by this technique. The nutrient solution also does not stagnate around the roots, making infection by pathogens less likely.
You will be able to control the watering and feeding of your plants and modify it to your local climate and weather.
This method can be used for many types of crops – even root crops that are trickier to grow.
However, it could be a bit much to handle for beginners and those who do not have a background in hydroponics. Setting it up is complicated, and it is also complex to run. This is one of the least simplistic of all the methods.
The ebb and flow system depends on the proper functioning of the pump. If the pump gets stuck and misses an irrigation cycle, you might not realize it immediately.
The pump can also become easily clogged due to the amount of work it has to do, and broken roots may end up inside the pump. The pipes can also become clogged and prone to leakage because of the amount of water involved.
The pump in this system is also quite noisy, so keeping it inside your house may be annoying. You may have to keep it outside or in a greenhouse.
This method is one that might be better off left to the professionals. The complicated system is not very cheap and has several drawbacks.
5. Wick system
This method is simple but effective. It may not be the best hydroponic system, but it is inexpensive and solves a lot of the problems of deep water culture by using a wick.
If you want to give this method a try, you will need a grow tank, a reservoir, wicks made from rope or other spongy material, and a growing medium such as expanded clay or coconut coir.
This method works by simply dipping the wicks in the reservoir where the nutrient solution is and putting the other end of the wick in the grow tank. Fill the tank with growing medium and you can plant your crops right into it.
Due to capillary action, the nutrient solution will move up the wick from the place where there is more solution to the place where there is less solution. Thus, as the roots of the plant absorb the solution from the wick, the wick absorbs solution from the reservoir, making a continuous flow.
This method is a good choice because it is inexpensive, not overly complicated, and operates without the need for electricity. It also recycles the nutrient solution.
Using the wick system, the amount of nutrient solution absorbed by the plant is autoregulated.
This method also provides the plant with good aeration.
The downsides of this method include not being suitable for vertical gardens or towers.
Because of the wick, the plants also do not have a chance to dry out, because the moisture climbs up the wick continuously. This system also still has to deal with fungi, bacteria and algae due to the grow tank being humid all the time.
This method is also not suitable for bigger plants, because they have a faster nutrient absorption rate than a wick may be able to sustain. The wick can only really provide the plants with a limited amount of nutrient solution. Furthermore, for the wick to be effective, it cannot be too long.
6. Deep water culture
Deep water culture is the most classic of all the hydroponic methods.
It also uses a grow tank with a nutrient solution and an air pump that provides the plant’s roots with oxygen. The air pump helps more plants grow in a single tank.
You will need a grow tank into which the plants can dip their roots, an air pump, a reservoir for your nutrient solution, and a water pump.
The advantages of deep water culture are its simplicity and inexpensiveness. There are few elements and factors to consider, which means there are fewer parts to possibly break down and ruin the system. It also allows you to top up the nutrient solution and provides great aeration to the roots.
On the downside, in this method the nutrient solution is pretty much stagnant, which makes it a favorite place for pathogens to use as a breeding ground.
A simple air pump may not be enough to provide adequate aeration for the plants, because the plants nearest the air stone will absorb most of the air provided while the plants on the other end may end up receiving little to no air. You can try to remedy this by placing the air stone in the middle, but the plants on the outer edges are still going to end up with less air.
This method is not appropriate for vertical gardens and may occupy a lot of space in your home or indoor garden.
You can only really thoroughly clean the tank if you remove everything inside it, so you cannot clean it while it is functioning. This means you can only clean it when you plan to change crops.
Do not use this method for plants that cannot tolerate having their roots wet all the time, because with this system their roots will never be able to dry out.
You can use this method if you have a larger garden for the control it affords you over the aeration and feeding of your plants. However, it does have a lot of shortcomings that have made professional gardeners use it less and less over time.
There are many different hydroponic methods, and choosing which one to use in your garden will depend on your budget, available space, and the type of plants you plan to grow in your hydroponic garden.
You do not need to choose one method and stick to it forever. For now, look at the different options, choose the method that will cater to the needs of your planned crop, and start from there. You can always try a different method next season.