In a nutshell, hydroponics is a method for growing plants and vegetables that does not require soil. As we’ll see over the course of this introduction, this has a number of distinct advantages over traditional methods for growing plants, either as a hobby or for yield.
So how does this work? The name is the first indicator of what hydroponics boils down to, with the term ‘hydro’ meaning water. Here, instead of using soil, the plants will instead get everything they need from water. More specifically, they will get what they need from some form of mineral nutrient solution, which will contain all of the nutrition that the plant needs to thrive without the need for soil to act as a medium or means of delivery.
Growing plants in this way makes it much easier to grow the plants indoors and means that you can pack far more plants into a smaller space. They often tend to be healthier and in short, it is generally regarded as a more ‘efficient’ means of growing plants.
Of course though, hydroponics has its own challenges and it actually takes a number of forms. You cannot simply place a plant inside a vat of water, or it will drown. The method to hydroponics then involves finding ways to keep the plants out of the water and to support them as they grow, while still giving them all the hydration and nutrition they need.
How Does Hydroponics Work?
To better understand how hydroponics might work, it can be useful to first understand what plants need in order to stay alive and how they function.
Most likely, you have a fairly good understanding of this already from high school science. But perhaps you also have some incorrect assumptions about what plants actually need?
The most important assumption we need to address here, is the idea that plants might need soil in order to survive and thrive. Because we mostly grow plants around the house or outdoors by using soil, it only follows that we might be drawn to this conclusion.
But in reality, soil only serves a few different jobs. One is that it serves as a solid foundation for the plants to anchor themselves into. This of course is one of the jobs of the roots, which will branch their way out and spread through the soil in order to fix the plant in place and prevent it from falling over or blowing away.
The other job of soil is to provide a kind of filter through which the plants can absorb liquid and nutrients. If you were to simply place a plan on the ground without planting it in soil, then its roots would have no way to access nutrients and water would just quickly drain away before it could be of any use.
Good soil for plants then is aerated as this makes it easier for roots to climb their way through and to get a firm hold. What’s more, is that this allows rain water to penetrate more easily, where it will absorb the water-soluble vitamins and minerals in the upper layers and then deliver those to the roots for the plant to enjoy.
But just because soil is one convenient way of fulfilling those roles, it is not the only way. Rather, it is just as possible to use a plastic rack in order to suspend plants above the water and to allow the roots to dangle below. This way, the roots can gain access to water that is infused with the same nutrients but it will be held firmly in place.
This is just one way in which hydroponics might work however and there are actually several more…
The Types of Hydroponics
There are numerous different types of hydroponics which all alter the ways in which the plants are kept suspended in place while also being fed the nutrients and water that they need in order to survive and thrive. Here are some of the most common and popular forms…
Deep Water Culture
Deep water culture is also called ‘DWC’ or ‘the reservoir method’. We’re starting with this one, seeing as it is the simplest, easiest and probably the most common method used for hydroponics farming. This is also the main form of hydroponics that will come to mind for most people when they hear the term.
If you’ve ever seen rows of white plastic containers with plants being held in place, then this is DWC.
The plants are this way held in place as we described, while the roots are left to dangle loosely into the water below which is infused with nutrients. Thus the plants can drink up the water and the nutrition without worrying about getting blown away.
Of course, the potential risk with DWC is that the plants might drown. This issue is prevented through the use of an aquarium pump, which oxygenates the tank.
This method is popular thanks to its simplicity and scalability, though it does have its drawbacks as well, which we will get to shortly.
Nutrient Film Technique
This method also has a popular acronym (like DWC), which this time is ‘NFT’. NFT essentially involves the use of a continuous flow of nutrients which will run over the top of exposed plant roots. In this case, it is gravity that is doing all of the work by letting the water flow down a gradient and thereby run over the top of the roots.
This method once again manages to strike the necessary balance by ensuring that the roots have a constant supply of hydration and nutrition while also preventing them from drowning. Because the water is constantly moving, there will be plenty of gaps in it to allow the plants to breathe.
In aeroponics, there is no body of water involved at all. Rather, the plants will instead be provided with nutrition via a cloud of mist that is sprayed over the roots. Once again, this is an effective way to deliver nutrients that doesn’t run the risk of drowning the plant by smothering the roots.
There are two different types of aeroponics that can be used as well. One form uses a nozzle in order to emit a spray and this will then hydrate the roots. Another kind will use what is called a ‘pond fogger’, which requires a Teflon coated disc to reduce the amount of necessary maintenance.
While aeroponics might sound like an entirely different activity to hydroponics, it is actually very much the same in practice and the science is essentially very similar too.
Other Kinds of Hydroponics
Believe it or not, that’s still not all of the different kinds of hydroponics available to us! Another option for example is wicking, which involves using a material as a growing material which will then have a ‘wick’ that carries water from a reservoir up to the plant.
Then there is the drip system, which provides a slow feed of nutrient solutions into a growing medium such as rockwool or coconut coir.
The Benefits of Hydroponics
So that’s the basic idea behind hydroponics and some of the techniques that you can employ to get started. But why exactly would you want to get rid of soil in the first place?
For hobbyists and commercial hydroponics enthusiasts, the answer will often come down to space and convenience. If you don’t have space in your garden to grow plants and flowers, then you might want to move your growing activities indoors instead. This would potentially risk creating a lot of compost mess and it’s not something most people will like the idea of.
But if you instead use hydroponics, then you won’t need to bring soil or plant pots into the home and instead you can make do with a simple container of water and some plastic holders for your plants.
There’s also something that’s a little more rewarding and interesting about hydroponics for some people. We all like to be different and hydroponics has a somewhat futuristic and certainly very different vibe to it. It’s an exciting and new type of gardening that you can enjoy showing off to friends and other visitors and it’s certainly a great talking point! Like all gardening, hydroponics rewards dedication, attention to detail and a scientific mind.
However, on a larger scale, hydroponics has a huge amount of potential and makes a lot of sense for larger organizations and communities.
The main reason for this is that hydroponic gardening results in better yield and efficiency.
The reason for this is that you will be able to grow more plants in a smaller space, which immediately means that you’ll be able to get more return on your time and space investment. When you grow plants hydroponically, they will have their roots submerged directly into a solution filled with nutrients. This then means that the roots will have no need to spread out and reach through the medium and can instead grow directly downward. This means that the plant will be ‘thinner’ and thus you can place more plants next to each other.
At the same time, the abundance and easy accessibility of nutrients means that the plants will be able to thrive in a relatively small amount of space without robbing one another of nutrients. Even the light will be provided via ‘grow lights’ (normally LEDs), meaning that there will be less concern about the plants overshadowing each other.
In fact, because hydroponics means that the plants will be grown indoors, you’ll be responsible for controlling the climate in its entirety. That means that you aren’t going to have a sudden strong gust of wind that destroys your plants, or a draught that leaves them without hydration.
And because you’re in control of the climate, that also means that you can theoretically decide precisely what kind of plant you want to grow. How about something a little more exotic?
This is just one reason that hydroponically grown plants also tend to be healthier. Another is that many of the downsides associated with soil are removed. For instance, you won’t need to deal with pests like slugs as much and disease in general will be much less common.
Finally, when you grow plants hydroponically, you are controlling the nutrients far more precisely too and ensuring that they are efficiently delivered. This means that the plants will get to grow up to be much bigger and healthier and to potentially grow larger, more nutritious fruits and vegetables.
Hydroponics is an ideal choice for those that want to grow plants and vegetables organically then, as the need for synthetic fertilizers and pesticides is greatly reduced.
Nothing is perfect though of course and hydroponics does also have its downsides.
The most notable issue with hydroponics is that they can be quite susceptible to changes in temperature and lighting. And because everything is controlled by systems and all plants are subject to the precise same conditions, it is possible to lose a lot of yield very quickly. Often the lighting systems used will be on a controlled cycle to mimic the rise and fall of the sun for instance but if this should become damaged and get overly hot, then it could potentially kill an entire room of plants. Likewise, if you are using a deep water culture system, then you will be very reliant on the pump operating correctly. If this should stop, then all the plants can be drowned immediately.
These risks are relatively minor though as long as due care and attention is given to the plants. In the grand scheme of things, hydroponics represents a much more efficient and productive way to grow plants that is also a lot of fun and very interesting. This is certainly something worth looking into if you have any interest in horticulture, especially if you don’t have much space in your garden.
And for the rest of us, we can sleep easy knowing that hydroponics are helping to feed more of us, more efficiently!