What Is Hydroponic Gardening?

Medically Reviewed by Jabeen Begum, MD on November 09, 2022
Written by Shayan Kashani
5 min read

As we become ever more conscious of our environmental impact, developing and adapting sustainable practices is no longer just trendy but economically and ecologically vital. An area where these realities are more prevalent than ever is sustainable agriculture — namely, hydroponic farming and gardening. 

The use of hydroponics in agriculture isn’t new, but recent developments have made a once-industrial practice accessible to anyone. Regardless of where you live or whether you have any outdoor space, you can now grow your fruits, herbs, and vegetables at home, even in the dead of winter.

Here, we’ll take a closer look at hydroponics, how they work, how to set up your own home garden, and the numerous benefits of hydroponic agriculture.

It’s believed that the Hanging Gardens of Babylon — going as far back as 600 B.C.E. — were maintained by a river through a pulley water system known today as hydroponics. 

In the 19th century, German botanist Julius Sachs was the first to discover that plants didn’t need soil but only the nutrients from the microorganisms in the ground to survive. In the 1860s, he published the “nutrient solution” formula for water-based farming, which is the foundation for modern hydroponic agriculture.

In 1937, American scientist W.E. Gericke further investigated the practice by showing how plants grown in water uptake nutrients more efficiently than traditional farming, leading to higher yields and better quality crops. 

Today, hydroponic agriculture is considered one of the best methods of growing plants in terms of quality, yield, and environmental impact.

Hydroponic gardening is a sustainable method of growing plants without needing soil or natural light. Nutrients dissolved in water feed the plants essential minerals, and LED lights tailored to the plants' specific energy needs replace the sun, allowing hydroponic farms and gardens to be indoors. This method is also known as controlled environment agriculture (CEA), climate-proof farming, or indoor vertical farming.

Although you can grow any plant hydroponically, people most often use the practice to produce herbs, leafy greens, and greenhouse crops like peppers, cucumbers, and tomatoes. Hydroponic gardening is space-efficient and uses less water than typically needed for gardening in soil. 

Developments in hydroponic technology now make it possible for you to build and maintain a hydroponic garden at home that produces crops year-round.

Modern hydroponics are sophisticated methods of providing light, air, and nutrients to plants in controlled environments. There are three key elements to hydroponic systems: 

Nutrient solution. A nutrient solution is dissolved in the water reservoir that feeds the plants. This solution mixes major nutrients like phosphorus, nitrogen, potassium, magnesium, and sulfur, along with low concentrations of trace elements like copper, iron, and zinc. 

Oxygen. Most hydroponic systems use an air pump and air stone, typically used in fish tanks, to produce oxygen bubbles and keep the water reservoirs properly aerated. 

Potential hydrogen (pH) monitoring. Additionally, pH levels — which determine the acidity of the water — are closely monitored and maintained between a pH of 5.8 and 6.2 for optimal results. Citric acid lowers pH, while baking soda raises it. 

Lighting. Outdoor or summer hydroponic gardens can use sunlight. But indoor systems and winter gardening require artificial lighting, typically fluorescent or LED bulbs, that can emit different spectra of light depending on what you’re growing.

There are three main methods of hydroponic agriculture, each with slight variations and advantages depending on the type and size of the crop.

The ebb and flow technique. This technique involves plants being partially flooded or submerged in a tank or tray of nutrient-rich water. After the plants have taken up the nutrients, the water is actively replaced and reused. Also known as "deep water culture," this is the simplest and most common type of hydroponic system used in small-scale operations and home gardens. 

The nutrient film technique. This technique involves plants angled in a tray above a reservoir of aerated, nutrient-filled water. A water pump runs a steady stream continually over the plants, providing them with water, air, and nutrients as it cycles through the tray and water reservoir. The nutrient film technique is the most common hydroponic system used on an industrial scale.

The wick system. Also common in home and indoor gardens, this system involves passively feeding nutrients to plants through a wick or string running from the roots to a nutrient-rich water reservoir. Typically, plants grown in this hydroponic system are placed in rock, sand, or clay to help anchor their roots.

There are numerous benefits to having a hydroponic garden. 

These gardens are cheaper to build and maintain, require less space, and can be sustained indoors. These benefits give hydroponic gardening the potential to grow fresh food even in areas with extreme weather or poor-quality soil.

A controlled environment also allows for measuring precise amounts of nutrients, water, and light given to plants. This optimization yields the highest-quality crops.

Additionally, since there’s no soil in hydroponics, crops are not exposed to any pests or microbial diseases usually present in the ground. As a result, there’s no need for herbicides or pesticides, resulting in better yields and higher-quality crops. 

Finally, the environmental benefits of hydroponic farming and gardening are staggering. Compared to traditional agriculture, hydroponic systems use up to 90% less water, a fact that becomes more critical to long-term agricultural sustainability each year.

You can easily set up a hydroponic garden to grow fruits and vegetables at home — indoors or outdoors — with the following basic components:

Growing system. You can buy a deep culture hydroponic system, but it’s just as easy (and cheaper) to build your own. You can use any container that holds water — like a gallon bucket or plastic bin — as a water reservoir for a home hydroponic garden. You’ll also need a support system to hold the plants upright, like a bucket lid with holes drilled into it. Finally, you’ll use pots with holes or slits to allow the plant roots to reach and partially submerge in the water. The size of these components (container, lid, pot) will depend on what you plan to grow.

Lighting. Fluorescent or LED light bulbs will supplement or replace natural light for indoor and winter gardens. The light spectrum ranges from red to blue, with many bulbs producing mainly one or the other. For optimal results, a combination of both is recommended.

Aeration. Plants will sometimes receive air naturally through the gap between the water reservoir and the partially suspended plant. Alternatively, an air stone, basically a synthetic "stone" full of holes, is connected to an air pump that pumps oxygen through the stone. This results in tiny air bubbles going into the water, similar to what you see in most aquariums.

The biggest challenge of setting up a hydroponic system is the initial costs associated with buying the materials, like lights, seeds, plant racks, and water-feeding systems. These costs are minimal for personal and home gardens. Still, startup farms and small-scale operations looking to switch from traditional to hydroponic agriculture must first invest in the right equipment.

Like all agriculture, hydroponics also comes with its unique challenges associated with maintenance. Ensuring optimal heat, airflow, and humidity is critical to the success of hydroponic farms and gardens.

But with the right practices, you can easily overcome the maintenance challenges, and your initial investments will ultimately lead to higher yields, profits, and long-term sustainability.