Imagine walking into a farm where rows of lettuce, herbs and vegetables are growing neatly in pipes or stacked trays. Their roots are not buried in soil. Instead, they dangle into water, while pumps quietly move a nutrient-rich solution through the system.
It may look like farming without one of its most basic ingredients. But hydroponics works by giving plants, in a controlled way, many of the things they normally obtain from soil.
So, how does it actually work?
What plants get from soil
When we think of soil, it is easy to assume that plants “eat” it. In reality, soil mainly acts as a support system and a storehouse from which plant roots access water and essential nutrients.
Hydroponics separates these functions.
The plant is supported using materials such as coco peat, rockwool, perlite or clay pellets. These materials hold the plant in place but generally do not provide its nutrients.
Coco peat, rockwool and clay pellets support plants while nutrients are delivered through water. Photograph: (Green Assets)
Instead, the nutrients are dissolved in water and delivered directly to the roots.
This includes nutrients such as nitrogen, phosphorus and potassium, along with calcium, magnesium, sulphur and smaller quantities of elements such as iron and zinc.
In simple terms, the soil is removed, but the things the plant needs are not.
From water to nutrients
This is where the technology gets interesting.
A hydroponic setup has a reservoir containing water mixed with carefully measured nutrients. Depending on the system, pumps can circulate this solution through channels, drip it onto the roots or keep the roots suspended directly in oxygenated water.
One common method is called the Nutrient Film Technique (NFT). Here, a thin stream of nutrient-rich water continuously flows along a channel, allowing the roots to absorb what they need.
Another is Deep Water Culture, where the roots remain suspended in nutrient-rich water while an air pump supplies oxygen.
That oxygen is important. Roots need oxygen for respiration, so simply keeping them submerged in stagnant water would not work.
What controls the plant’s growth?
Hydroponics is not simply about putting a plant in water. The technology lies in controlling its growing conditions.
Farmers can monitor the pH of the nutrient solution, which affects how easily plants can absorb nutrients. They can also monitor electrical conductivity, which provides an indication of the concentration of dissolved nutrients.
Water levels, temperature, humidity and light can also be monitored, particularly in controlled environments such as greenhouses and indoor farms. Sensors and automated systems can increasingly help farmers make these adjustments.
For indoor farms, artificial grow lights can provide the light plants need for photosynthesis. In greenhouses and outdoor systems, sunlight can do the job.
For Gujarat farmer Yash Vora, hydroponics offered a practical answer to a problem he was struggling with for long: water.
Sensors can help farmers monitor pH, nutrients, temperature and other conditions that affect plant growth. Photograph: (Agriplex India)
He now grows cucumbers, tomatoes and coloured capsicums using a system where water and nutrients are given directly to the plants in controlled amounts.
Brio Hydroponics helped him set this up. The company builds hydroponic farms where farmers can keep a closer watch on things like water, nutrients and pH, instead of leaving everything to soil and weather.
Here’s how Brio Hydroponics is helping farmers like Yash grow with less water, and what it takes to set up a hydroponic farm in India.
Why grow plants this way?
For farmers like Yash, one of the biggest advantages is control.
Because nutrients and water are delivered directly to the roots, farmers can manage what the plant receives rather than relying entirely on the conditions of the soil. Nutrient solutions can also be recirculated, allowing hydroponic systems to use water efficiently.
The method can also make farming possible in places where good agricultural soil is limited. Hydroponic systems can be used on rooftops, in greenhouses and even in vertical farms, where plants are grown in stacked layers.
Hydroponics shows that sometimes, growing more sustainably begins with rethinking what plants really need. Photograph: (Hydropolis Krakow)
It is already being used for crops including leafy greens, herbs, fruits and flowers.
Of course, hydroponics is not a magic replacement for traditional farming. Systems can require an initial investment, technical knowledge and regular monitoring. Many setups also depend on electricity for pumps and, in indoor farms, lighting.
But the underlying idea is remarkably simple: plants do not necessarily need soil. They need the resources soil helps provide.
By delivering those resources directly through water, hydroponics turns farming into a carefully managed system of roots, nutrients, oxygen, water and light — opening another way to grow food where conventional agriculture may be difficult.
This story is part of “How Does It Work?” — The Better India’s series that takes the everyday things you see, use and rely on, and uncovers the clever technology, design and sustainable thinking that makes them work better. From the objects in your home to the systems around you, we break down the ideas behind them in simple, easy-to-understand language. Because innovation isn’t always about futuristic machines or complicated technology. Sometimes, it’s hiding in the things we use every day.
