What is Hydroponics?: An Intro to Planet-Friendly Planting

No soil, no problem. Hydroponic growth is set to change farming as we know it…

We know that plants need water and nutrients to grow. While soil is a great medium to deliver these, it’s completely possible to grow in other ways. Hydroponics (“hydro” meaning water and “ponics” meaning “toil” or work) is the process of growing plants in nutrient-rich water. Instead of soil, growers may use organic substances like clay pellets, coco coir, rockwool, or perlite. 

It’s being looked into to solve all kinds of current issues: David Attenborough’s recent Netflix documentary, A Life on Our Planet, explored the Dutch increasing their farming output tenfold through hydroponics. NASA’s Kennedy Space Centre is currently growing onions to see if they’d survive in space.

Hydroponics has the potential to take our produce quite literally to another planet. But, as huge as the possibilities are for growing in this way, it’s possible to grow on as small a scale as your own back garden. That’s what makes it so exciting.


How can you grow hydroponically?

Admittedly, it’s not just water and seeds. A hydroponic system needs some specialist equipment to keep plants in optimal conditions. However, this equipment is widely becoming available to the everyday grower, and you don’t have to be an expert to start setting up. 

You can grow almost anything in a hydroponic system, but the following fruits, vegetables, and herbs work particularly well:

  • "Leaves" such as lettuce and spinach;
  • Tomatoes;
  • Bell peppers;
  • Cucumber;
  • Berries (such as blueberries and strawberries);
  • Beans;
  • Grapes;
  • Cantaloupe melons;
  • Herbs such as basil and spinach.

You can also grow flowers and ornamental plants like orchids and bonsai trees using hydroponics.


What do you need for hydroponic growing?

The joy of hydroponics is that you can use as much or as little equipment as you can afford. However, if you’re looking to regularly grow fruit or veg in indoor conditions (especially in colder, darker climates like the UK) having the right tools in place will make for faster, more cost-effective results.

The most popular pieces of equipment are as follows:


Grow lights

It’s common knowledge that all plants need light in order to grow! If you live in an area with few daylight hours, or you’re growing in an environment such as a grow tent, your plants will more than likely require some extra help receiving a full spectrum of light. 

Grow lights hang above your produce and are designed to provide all the benefits of natural sunlight that a plant needs. LEDs are widely considered the most popular and cost-efficient light fixtures today - just as you most likely have in your lights at home - but other options, such as HID and HPS (like you’d find in a yellow street lamp) are also available. 


Grow tents

Grow tents are used to store and grow your plants. They’re collapsible structures which block out all the light from outside. Instead, you place your grow lights inside and let your plants grow in completely controlled conditions. A reflective silver material inside the tent helps to maximise the effectiveness of your grow light and help keep running costs down. 

It might seem counterintuitive to place your plants in a dark space and then add lights, but tents help to provide total control over the conditions of your growing space. Plants thrive on predictability: you can maintain a consistent temperature, climate and humidity level throughout the year. 

Grow tents can range in size from less than a square metre to the size of your average bedroom. This makes them a hugely versatile option for those looking to grow hydroponically, regardless of available space. 


Plant nutrients

Nutrients are another essential component of healthy plants. Just as you can buy fertilisers for plants grown in soil, hydroponic nutrients dissolve into your reservoir or tank and are taken in through your plants’ roots. 

You’ll most often find them in liquid form, though powders are common too. Nitrogen, phosphorus, and potassium (known together as NPK) are the primary nutrients for any plant - though there are a multitude of different nutrients out there designed to accelerate plant growth, improve the taste of your produce, build healthy roots, and make your plants more resilient against disease.


Ventilation equipment

Plants benefit from fresh air, just as they would in an outdoor breeze. Placing a fan in your growing space helps to circulate oxygen to all plants, maintain a consistent and cool environment, and blow out stagnant or hot patches of air. 

Plants naturally emit CO2, which can lead to some bad smells if they’re kept confined for long periods. Carbon filters and ducting aren’t necessary for beginners, but they can help to eliminate odours in your indoor grow space and transport them out into the open. 


Temperature monitoring equipment

Again, plants thrive on consistency. You’ll need to carefully control the temperature of your environment if you’re growing hydroponically, especially since your lighting will also produce heat. Beginners will benefit from a simple thermometer on the wall to make sure things are running smoothly. On a larger scale, thermostat-controlled chillers are available to constantly monitor and automatically adjust your reservoir temperature - but these might not be a budget-friendly option to start with! 


Where can I buy hydroponic equipment in the UK?

There are hundreds of hydroponics stores across the UK, both online or physical shops if you prefer to browse in person. These stores will likely have the largest ranges of equipment available. 

Luckily, hydroponics’ potential for sustainable, local growing means that it’s a booming industry. Popular hardware and gardening stores sell drip-feeding and irrigation kits, as well as a range of fertilisers - and even larger equipment like grow tents are beginning to come into the picture. 

Perhaps you’ll find that one of these types of stores, or a mix, are right for you. Cheap hydroponics equipment is readily available more than ever before, meaning you can choose according to your budget and scale. 


What hydroponics methods are there?

Here are six different methods of growing hydroponically. Each will require their own setup, and each produces unique benefits:

Drip system

A pump located in the reservoir delivers nutrient solution to plants in drips at regular intervals. This is the most popular method of hydroponic gardening, perhaps because it’s so simple but can be upscaled to customise feed timings and even deliver different nutrients to plants in the same tank. 

Flood and drain system

Also known as “ebb and flow”, this involves flooding your growing area at regular, timed intervals. In between the floods, the nutrient solution flows back into the reservoir to be used again. 

Deepwater culture

This is sometimes called the reservoir method and is one of the most basic methods of hydroponic growing. The plants’ roots are placed directly into a tank of nutrient solution. An air pump (like one in an aquarium) is used to provide oxygen and prevent the plants from drowning. 

Nutrient Film Technique (NFT)

This method runs a very shallow stream of nutrient solution over a plant’s roots. The grow tray must be placed at angle, so that the solution can flow downwards into a lower tank. It is then carried back up through a submersible pump to be reused. 


Aeroponics works in a similar way to traditional hydroponic methods - but instead of being submerged in water, plants are kept in a humid, enclosed area and sprayed with nutrient-rich water vapour. 


A “wick” - usually a rope or strip of cloth - is placed into a pot alongside a plant and reaches out into the reservoir through a hole in the bottom of the pot. The wick draws up the nutrient solution and distributes it into the substrate inside the pot. 

Wicking works without the need for any motors or pumps, making it a highly cost-effective approach and great for beginners. 

What are the benefits?

You might be able to tell already that hydroponic growing has a wealth of benefits. It’s possible on any scale, from a tray of herbs to an entire commercial farm. 

  • Reducing carbon footprint
  • On a worldwide scale, the main appeal of hydroponics is that its lower impact on the environment. It uses significantly less carbon than traditional farming; it uses 80% less water; and it can produce up to twice the yields. Plants tend to grow faster and larger, increasing production turnover and reducing food waste by consistently meeting quality standards. 

    Hydroponic growing reduces the carbon emissions caused by transportation of produce. It also requires much less space than agricultural land, since hydroponic plants can be suspended and stacked. 

    As well as this, it makes urban and local growing more feasible, increasing community sustainability and reducing the need to rely on multi-billion-pound corporations for food. 

    It doesn’t matter if you’re in the heart of London with a hundred chain cafés at your fingertips, or out in the sticks and want to fend for yourself - hydroponic farming can provide you with a low-cost, environmentally friendly, and independent means of living.

  • Utilising uninhabitable land
  • Hydroponics has been used for years, but it offers some distinct advantages in the 21st century. Climate change is more of a threat than ever, and it’s depleting arable land at alarming rates. We’ve lost a third of it in the last 40 years, according to experts. 

    While it might not be able to restore it to its original state, it’s possible to grow hydroponically in these areas. This also applies to uninhabitable areas like deserts and arctic climates. 

  • Ending “seasonal growing”
  • A larger, more globalised population also means a greater demand for foods. What if you went to the supermarket, only to be told that lettuce is out of season and they’ve stopped importing bananas? Readily-available, year-round produce from all over the globe is expected in more economically developed countries (MEDCs). It also plays a part in climate destruction. 

    Hydroponics removes the need for certain weather conditions to grow certain plants, meaning that countries could sustain themselves and lower their importation footprints for good. Hydroponics in the UK could revolutionise the food we're able to grow in our cold, dark climate! 

  • Surviving adverse weather
  • With global warming comes more extreme weather, more often. The UK saw three times the average rainfall in some areas in early 2020 - and we experienced the highest February levels since records began in 1766. 

    Entire farms could be, and have been, wiped out in this way. Growing indoors could help to protect our produce, as well as securing farmers’ livelihoods. 

  • Fewer weeds, pests, and plant diseases
  • Because hydroponic conditions are so closely monitored, it’s pretty difficult to let anything unwelcome in. In the most highly-controlled hydroponic systems, specialised entrances prevent bugs and pests from reaching plants. Water, nutrients, and temperature are monitored 24/7, within just a millimetre or a tenth of a degree.

    These harshly-regulated conditions can equally be made to mimic outdoor growing, meaning that plants don’t miss out on the benefits of fresh air and light. 

    What next?

    Not only could it aid our climate crisis, but it also has the potential to line pockets. The worldwide hydroponic industry is predicted to be worth £8.8 million by 2025. 

    That said, it’s not a perfect solution. As much as we love hydroponics, it’s always important to consider the potential drawbacks of using “non-traditional” methods to grow: 

  • Expensive to set up
  • Many forms of hydroponic growing require an initial investment for equipment and space. Renting or renovating a piece of land to support this can be a costly first step. What’s more, many methods require electrical tools (such as pumps, lights, fans, and chillers). If you don’t choose efficiently, the bills could be unsustainable. 

    That said, it can cost as much or as little as you decide. If you want to start small in your back garden, with passive methods and natural lighting, the price is minimal. 

  • Potential for equipment failure
  • In short: if your pump fails, your plants could lose their entire oxygen supply. 

    Thankfully, many equipment has safety features like “auto-restarts”, which automatically switch back on following a power failure - but the effects could potentially be disastrous.

  • Requires regular monitoring
  • Again, the more advanced you make your setup, the higher yields you will produce. But there’s also more factors to keep an eye on. If you want to achieve the best results, you’ll need to keep an eye on anything that could stand in the way of your plants reaching top yields. 

    Water temperature, ambient temperature, water levels, nutrient concentrations, pH, EC, humidity, air circulation…these will all make or break the conditions of your growing space. However, traditional farming is hardly a breeze either! 

  • Waterborne diseases
  • While pests and airborne diseases are low-risk, waterborne diseases can have equally terrible effects on a plant. And, because they all share the same reservoir system, infected plants can spread disease much more quickly. 

    As discussed in the point above, regular monitoring is essential for maintaining a healthy climate for your plants to grow. 

    Whether you’re curious about growing flowers for fun or you’re setting out to build the next eco-friendly empire, hydroponics could be the solution. It offers unique benefits over soil, and presents a significant opportunity for local produce growing and climate change reduction. In our current world, it could become the future of farming. 

    Take a look around Growers House to see if we have the tools for you!