If I were to ask you the first thing that comes to mind when you think of the word hydroponics, there’s a good chance you would picture a large indoor space, with rows of fancy, modern LED lights attached to sleek shelves full of produce like tomatoes or lettuce. Or maybe you picture one of those fancy vertical hydroponic towers with a modern aesthetic.
If that at least somewhat resembles what you think of when you hear the word hydroponics, I don’t blame you. As modern, sleek, and sustainable-looking agricultural technologies continue to emerge, we are often marketed the idea that this is what hydroponics looks like. However, there are so many ways to engage in hydroponics beyond these modern, sleek-looking machines.
So, What Exactly Is Hydroponics?
The word hydroponics is derived from two Greek words: hydro, meaning “water,” and ponos, meaning “labour.” Together, it translates to “water working.” Essentially, hydroponics is about growing plants by supplying the nutrients they need through water rather than soil. As long as a plant is receiving its nutrients directly from a water-based nutrient solution rather than from soil, it can be considered a hydroponic agricultural method. Plants can still be grown in inert materials that provide mechanical support, such as coconut coir or rockwool plugs, but those materials aren’t providing the plant with its nutrients.
Despite how futuristic hydroponic machinery can look today, the technology isn’t new and dates back much further than the 21st century. There are many examples throughout history of civilizations growing crops in water as opposed to soil. The Hanging Gardens of Babylon and the Aztec chinampas, or floating gardens, are two examples commonly mentioned while discussing the history of hydroponics. In China, floating agricultural systems were also used and have been described as an early form of hydroponic cultivation, even though the term “hydroponics” did not exist at the time. There are also Egyptian hieroglyphic records dating back hundreds of years B.C. that describe cultivating plants in water. These examples highlight how the concept of using nutrient-filled water for plant cultivation is not a new concept.
Floating Agricultural Systems in China
Regarding modern hydroponic systems, much of the technical knowledge and understanding we use today began to develop during the 17th century. At the time, Belgian chemist and physiologist Jan Van Helmont conducted an experiment in which he discovered that plants obtain nutrient substances from water. At the time, however, researchers still believed that many of these substances found in water emerged from soil. It was not until the 19th century that an experiment conducted by Jean-Baptiste Boussingault, a French chemist, found that water was essential for plant growth because it provided hydrogen, while the hydrogen, carbon, and oxygen that made up the plant’s dry matter came from the air rather than the soil.
From there, scientists continued conducting experiments demonstrating that plants don’t technically need soil to grow. Instead, plants can be grown in a medium containing a water solution with the minerals they require. Further research identified the major nutrients that plants need in relatively large quantities to support normal growth. These included nitrogen, phosphorus, sulfur, potassium, calcium, and magnesium. Today, these are known as the macronutrients in hydroponics. Of these, nitrogen, phosphorus, and potassium are particularly familiar. You may recognize them as N-P-K, a common acronym used on fertilizers in agriculture and gardening. Later on, it was discovered that plants also need other elements in much smaller quantities. These include iron, chlorine, manganese, boron, zinc, copper, and molybdenum.
As our understanding of plant nutrition grew, new techniques and hydroponic systems were developed throughout the 19th, 20th, and 21st centuries. Over time, some of these systems began to resemble the “fancy” hydroponic setups and lighting technologies that we associate with hydroponics today.
Fun fact: The invention of plastics was a major turning point in the modern development of hydroponics. By using plastics to construct beds and tanks that were previously built from concrete, hydroponic growers were able to save money. It also led to the development of better pumps, time clocks, plastic plumbing, and other equipment that are still used in many hydroponic systems today. These technologies also allowed hydroponic systems to become computer-automated, which isn’t a huge deal if you’re doing this as a hobby at home and only have a couple of machines, but for people growing crops on a larger scale, it reduced both upfront investment and operational costs.
Even with all of these new inventions, machinery, and scientific knowledge developed over the last several hundred years, the basic concept behind hydroponics remains simple: growing plants using water to provide the nutrients they need, which has been practiced for a long time!
Hydroponics Doesn’t Have to Be Expensive or Complicated
This brings me back to my earlier point on how hydroponics is often viewed today. As modern, sleek, and sustainable-looking technologies emerge, we are often marketed the idea that this is what hydroponics is and should be. However, there are so many ways to engage in hydroponics beyond these modern machines. This connects to a broader issue in sustainability. Products that allow consumers to participate in “sustainable” or “green” hobbies are often marketed toward higher-income consumers, essentially excluding certain groups from participating in these activities. We see this with composting, for example, as many of the pre-built, modern-looking vermicomposting kits are often priced at over $300 dollars…
But you don’t need a bunch of fancy equipment to get started with hydroponics. One of my favourite examples of a simple and low-cost way to get started is the Kratky method. The Kratky method was first published in a paper in 2009 by B. A. Kratky. It is a passive, non-circulating method of hydroponics. In other words, you don’t need to constantly circulate the water, and you don’t need to manage pumps, complicated wiring, or wicks.
Essentially, the method works by suspending plants above a reservoir of nutrient-rich water. As the plant grows, its roots grow down into the reservoir and absorb the water and nutrients they need. As the water level decreases, part of the root system becomes exposed to air, allowing the roots to access oxygen while the remaining roots continue absorbing water and nutrients.
This method is well suited for growing lettuce and herbs. In my experience, by the time the plant has absorbed all of the water in the reservoir, the plant is already grown or nearly grown. At that point, you can simply harvest it rather than having to continuously maintain a complicated system. Depending on where you live and how much sunlight you have access to, you may not even need fancy lighting. And if you’re only growing herbs or leafy greens, the lighting requirements are generally less demanding and much less expensive to buy than those of fruiting crops such as tomatoes or cucumbers.
During the winter 2026 semester, when I did a four week class on hydroponics, I used yogurt containers as reservoirs. I cut a large hole in each yogurt lid to fit a net pot. The students and I then put coconut coir into the net pot to provide mechanical support for the lettuce. We then placed a lettuce seedling inside, added a nutrient solution to the water, and let the plant grow.
That’s all there is to the Kratky method. You can get started with something as simple as a yogurt container. And that’s just one example of how hydroponics isn’t limited to the giant greenhouses or modern, sleek-looking machinery we are often shown online.
Written by Catherine, of ABCompost
Sources:
Resh, H. M. (2022). Hydroponic Food Production : a Definitive Guidebook for the Advanced Home Gardener and the Commercial Hydroponic Grower, Eighth Edition (8. ed). CRC Press. https://www.indigo.ca/products/hydroponic-food-production