What Is Hydroponic Weed and How Do They Work?

Sophia Delphi July 01, 2022 - 8 min read
Fact Checked
Illustration of Growing Hydroponic Cannabis at Home

You constantly hear myths in the weed world.

You can’t get addicted to weed. (False. It’s not physically addictive. But marijuana use disorder, a psychological addiction, affects an estimated 9% of users.)

You should hold the smoke in as long as possible. (False. THC is absorbed by the lungs in just a few seconds. Long holds just make you cough more.)

Purple weed is the strongest. (False. The purple color is primarily the byproduct of a specific flavonoid and the plant’s acidity level. Color has nothing to do with potency.)

Here’s another common belief: hydroponic weed — the flower produced by plants grown in water — is better than bud grown in soil. 

True or false? Let’s find out, after learning a little more about how hydroponic cannabis is grown.

What Is Hydroponic Growing?

Hydroponic growing is nothing new. It’s been researched for centuries and has been used successfully to grow crops since the 1930s.[1]

Many cannabis producers have adopted the technique in recent years, also with great success. More and more home weed growers are using hydroponics as well.

The word hydroponics essentially means “working with water” in Latin. That fits the image that most people commonly associate with the growing technique. They visualize plants sitting in water instead of soil, with all sorts of tubing and high-tech equipment surrounding them.

Hydroponic growing doesn’t have to be that complicated. You start, of course, with the absolute necessities: plants, pots, light, and air. But the only things you need to add for a simple hydroponic grow are a reservoir of water, an inert growing medium, and nutrients.

All of the “fancy” hydroponic equipment you may have seen in pictures certainly makes the process easier and much more productive. A commercial grower might not even consider raising a hydroponic crop without water channels, pumps, irrigation tubing, and timers.

However, the justifications for hydroponic growing become clear once you understand the roles of its three primary components.

Water: The Key to Hydroponic Marijuana

We all learned in elementary school how plants grow. Their roots extend into the soil, where they seek out and absorb nutrients and water. Pressure forces those essential elements through the plant’s stems, so they can reach the leaves and buds.

In hydroponic weed growing, there’s no soil. Instead, roots hang in the air below the plant, where they can contact a reservoir filled with water.

Since the plant doesn’t have to expend energy seeking out water and nutrients, it can focus all of its energy on growth. The result: bigger, healthier plants and faster harvests.

You’ve probably realized that simply letting a weed plant’s roots contact a tub of water isn’t enough, though.

Best Nutrient Solution for Hydroponics

No plant can grow without an ample supply of nutrients. Hydroponic weed plants can’t find them in soil, so the grower has to provide them.

The right amounts of nitrogen, phosphorus, and potassium are crucial for proper and productive growth. Other minerals like calcium and magnesium are important too. However, they all have to be made available to the plants in the proper ratio.

That’s where water comes in. Growers can add those nutrients to the reservoir, and weed plants can easily absorb them with virtually no energy expense. Some of the fancy equipment we’ve mentioned is used to carefully time and monitor the availability of nutrients, but you can certainly grow cannabis plants by doing that work on your own.

Inert Growing Mediums for Hydroponic Systems

Image of Hydroponic weed being grown

A normal weed grow uses soil as its “growing medium.” Soil supports the plants, facilitates their root growth, and provides the nutrients they need.

As we’ve discussed, plants grown hydroponically don’t get nutrients from the soil. But they still need physical support and a medium in which their roots can develop. That’s what an inert growing medium provides — a sturdy, semi-solid “base” in which the plant can grow. (Inert simply means it doesn’t contain nutrients or organic material.)

Many inert growing media can be used for cannabis plants, including clay pellets, coconut fiber, Rockwool (which is essentially spun rock fibers), vermiculite, and perlite. Each has its advantages and disadvantages, but they all work well for weed plants.

Methods of Hydroponic Weed Growing

A complete explanation of the techniques used in hydroponic growing could fill a book. Those details have filled many books.

The most important consideration, though, involves the management of the water reservoir and the nutrients fed into it. There are several common approaches.

Deepwater culture is the most popular method for home growers. Plants are grown in mesh pots placed into a larger water reservoir, with a pump that circulates the water and adds oxygen. Growers add nutrients to the reservoir regularly.

These methods are more commonly used by commercial growers:

  • Drip Irrigation: Nutrients are fed directly to plants every few minutes via tubing and a timer system, and excess water flows back into the reservoir.
  • Ebb and Flow: Plants are flooded with a nutrient/water solution every few hours; the water drains into the reservoir and is reused.
  • Nutrient Film Technique: Plants are side-by-side in long channels, through which the nutrient/water system runs.
  • Aeroponics: Plants are suspended in mid-air in a humid chamber, and their roots don’t touch the water. Instead, they’re constantly misted with a nutrient solution.
  • Deepwater Culture: Plants are submerged in nutrient-rich water, which is then pumped with oxygen.

That’s a lot of possibilities. Do the methods produce a better product?

Is it Better to Grow Weed in Soil or Hydroponics?

Here’s our original question: is hydro weed better?

Here’s the honest answer: not necessarily.

The key determinant of potency, flavor, and aroma is the weed’s strain. A strain with low THC content isn’t going to get stronger just because it was grown in water instead of soil. And carefully-cultivated plants grown in soil will always produce better flowers than ones that haven’t been grown properly in water.

The reason hydroponically-grown weed can be better is that it gives experienced growers complete control over the nutrients their plants receive. That type of control and attention to detail is required to produce top-shelf cannabis.

So it can be better. Is it?

There’s been no research comparing properly-grown hydro weed with weed properly grown in soil. However, anecdotal reports indicate that hydroponic growing may preserve more of the plant’s cannabinoids, terpenes, and flavonoids than traditional soil growing does.

There’s a flip side to consider. It’s difficult to use organic practices with these techniques, and limited research shows that hydroponic weed growers are more likely to use chemical additives or fertilizers. Some even use fertilizers containing heavy metals, which could make their products hazardous to consume.

In short, there’s no proof that hydro weed is any better than the stuff you usually buy — at least from a user’s perspective. For growers who can afford sophisticated hydroponic systems, though, the approach greatly increases their yields — and their profits.

Hydroponic Weed FAQ

Q: If hydroponic growing increases commercial yields, does that mean it’s also better for home growers to use?
A: It can be if the home growers can pay proper attention to their system and their plants throughout the growing cycle. Hydroponically-grown plants require less space, will mature faster, and produce more herb; that doesn’t just mean a greater yield, but it also lets you harvest more crops per year.

Q: This sounds expensive. Can someone who just grows for their use afford to use hydroponics?
A: A full-fledged, commercial-quality hydroponic system will probably be out of reach for those who only grow a couple of plants for personal use. But there are inexpensive starter kits, available for anywhere from $100-$500, that will let you dip your toes in the hydroponic water (sorry, couldn’t resist the pun). Just be aware that you’ll have to pay a lot more attention to your crop than you will if you grow your plants outdoors. Hydroponic growing makes the most sense for those who’d like to turn their passion for weed into a more time-consuming hobby.


  1. Patel, D. (2022). Cannabis use disorder. Addiction Medicine, 33-40.[2]
  2. Zacny, J. P., & Chait, L. D. (1989). Breath-hold duration and response to marijuana smoke. Pharmacology Biochemistry and Behavior, 33(2), 481-484.[3]
  3. Konczak, I., & Zhang, W. (2004). Anthocyanins—more than nature’s colors. Journal of Biomedicine and Biotechnology, 2004(5), 239.[4]
  4. Lenton, S., Frank, V. A., Barratt, M. J., Potter, G. R., & Decorte, T. (2018). Growing practices and the use of potentially harmful chemical additives among a sample of small-scale cannabis growers in three countries. Drug and Alcohol Dependence, 192, 250-256.[5]