5 Techniques To Grow Cannabis Hydroponically

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Added 23 November 2021

Hydroponic farming is fascinating as it offers some terrific benefits. It uses 90% less water, requires no soil, and can help you grow plants all year round. Plus, hydroponic plants also tend to grow faster, larger, and healthier.

Luckily, these benefits translate well to cannabis farming, too!

Hydroponic cannabis farming allows you to get better yields and more potent buds. It also offers different ways to grow from a simple setup in your bedroom to a full-fledged commercial operation. 

In this article, we will discuss five techniques to grow hydroponic cannabis in your home.

About Hydroponic Cannabis

Before we proceed, let’s understand hydroponic cannabis and how it is different from regular, soil-based cannabis.

Hydroponic cannabis grows in a nutrient-rich water solution instead of soil, using mediums ranging from clay pellets to deep-water buckets, and sometimes, even in a fish tank!

The hydroponic method is quite different from the soil-based method. In soil, the cannabis roots embed more profound into the ground in search of nutrients. However, in a hydroponic system, the setup provides nutrient-rich water-based solutions directly to the roots, enabling more efficient uptake.

Therefore, the plant can divert more energy into its stems, leaves, and flowers instead of the roots. Needless to say, your plants grow better because you have complete control over everything. 

There’s a lot of debate over how hydroponics is better than soil. But, in a nutshell, here’s why hydroponic systems are better than other ways of growing plants:

  • Doesn’t require too much water — Although the word “hydro” may make it seem like you need lots of water to grow plants hydroponically, plants require less water than other growing mediums. 
  • Doesn’t require a lot of space — Hydroponic plants need very little room to grow compared to other systems.
  • Grows faster — Although this is a matter of debate, hydroponic plants are believed to grow faster than plants growing in other mediums because you can control the exact amount of nutrients the plants receive. 

If we are looking at the pros, you must understand the cons too, so here are a few disadvantages you may encounter with hydroponic systems:

  • There is no room for errors — You will constantly have to check the pH, PPM, EC, and many other factors to ensure the plants grow properly. One small mistake, and you may walk into a room full of dead plants. Soil growing mediums are less forgiving where you have some time to fix errors, but the same isn’t valid for hydroponics. 
  • Expensive — Most plants growing in soil don’t need a costly setup. However, you will need to spend significant amounts on hydroponic setups. 

Two Main Types of Hydroponics Systems

Typically hydroponics can be divided into passive and active hydroponic systems. While active systems depend on electric pumps and air stones to generate oxygen to the plant roots, passive systems depend on capillary action to help the plants absorb the nutrient solution.

One of the most basic types of hydroponics is the wick system. As a passive method, it sucks the nutrient solution from reservoirs through capillary movements. Growing media includes perlite, vermiculite, coco coir, etc. 

Wick System

Another difference between active and passive hydroponic systems is that passive hydroponic systems are inexpensive and require minimalist designs. They don't need sophisticated technology to deliver the nutrients to the plant’s roots. They also don't need additional electricity to function normally. 

While there are many types of passive hydroponic systems, the wick system, and the Kratky method are popular techniques. Some cultivators believe that passive hydroponics systems don't need manual intervention; however, you may have to intervene at times and water the plants when the system fails to provide enough water required for the plants to grow.

On the other hand, active hydroponic systems use sophisticated techniques to deliver oxygen and water to the plant’s roots. Some examples of hydroponic techniques include DWC, NFT, aeroponics, drip system, and the Ebb and Flow method.

Drip System.png

While passive hydroponic techniques may work for beginners, active hydroponics are most suitable for commercial cultivators. Typically these systems are best automated and also provide water and oxygen at timed intervals to the plants.

Although active hydroponic systems are slightly more expensive than passive ones, you can take a DIY approach to pull it off successfully. To give you a rough idea, active hydroponic systems may take anywhere from $250 to $300 if you purchase kits, but it could be cheaper if you set it up on your own.

Choosing the Right Growing Medium

When you grow hydroponic cannabis, you need to choose a suitable medium for your setup at first. Some of the most popular growing mediums are:

  • Clay pebbles 

Porous clay pebbles are used to deliver high quantities of oxygen to the roots while maintaining water and nutrient retention levels. Also called hydroton, you may have to change the pH to make them suitable to grow cannabis. However, most pebbles are pre-altered, so you don’t have to change them. Growers cultivate cannabis and many other plants in small hydroponic plastic pots with holes at the bottom for the roots to pass through. 

  • Coco coir 


Coco coir is coconut husks ground up into smaller particles. They protect the roots from external factors and serve as a perfect germinating medium. In addition, coco coir encourages aeration and retains moisture. 

  • Perlite 

Also known as volcanic glass, perlite is porous and promotes aeration; however, it does not retain any water. 

  • Rockwool

These melted rock fibers are excellent water and nutrient-solution retainers and are perfect for cannabis breeds with high nutrient requirements.

5 Techniques to Grow Hydroponic Cannabis

Like there are many ways to consume cannabis, there are many ways to grow it hydroponically!

But, before we start, keep in mind that you should always monitor the pH at all times. Here's a chart to help you maintain the pH:

hydro pH

You can choose from many hydroponic setups to grow cannabis — some are suitable for mass culture and others for more basic grow room setups. Select your system after considering your expertise and budget.

Although the growing media and the setups vary, all hydroponic systems use nutrient solutions or water mixed with hydroponic nutrients. What differs in the design is how the water circulates along with the oxygen exposure. 

If you’re a beginner setting it up for the first time, it’s best to purchase ready-made setups. However, if you spend some time browsing through our Growdairies or articles that show you how to set it all up, you can make your own. 

All setups have buckets, air stones, pumps in common, and you’d also need a drilling machine to make some holes as well. 

Here are the five ways you can grow hydroponic cannabis:

1. Kratky Method


The Kratky technique is one of the easiest methods to set up a working hydroponics system. It’s easy to construct on your own, or you can purchase kits since it’s inexpensive compared to other setups. 

If you want to make your own, it’s pretty cheap and shouldn’t cost more than $30 to $40. You will first need to choose a container. Choose one carefully, depending on the number of plants you want to grow. This container will be the reservoir holding the nutrients, so ensure that you buy high-quality plastic. 

If you take the DIY approach, you will need to drill holes into this container. Then, it’s recommended that you paint them to prevent algae formation due to sunlight. Whether you grow indoors or outdoors, algae will eat up the nutrients meant for the plants. 

If you have budget constraints, you can also use a styrofoam lid instead of a plastic container to cover the reservoir. 

Never keep the container open because it invites pests that bring diseases along with them. In addition, the nutrient solution can start evaporating and affect the growth of the plant. Therefore, when shopping for your container, make sure you get something that comes with a lid.

Next, you will need some net pots to hold plants. The plants will grow irrespective of the size of the net pot, so you can choose a 3-inch net cup.

Coming to the growing medium, you can go with hydroton or perlite. As you know already, both growing mediums don't affect the pH and provide good aeration.

Next, you will need some nutrients to feed the plants. Always make sure you buy hydroponic nutrients because nutrients meant for plants growing in the soil will not help the plants grow to their maximum potential.

Last but not least, you will need a pH kit to test the pH of the water frequently.

As you can see in the image, the plants are inserted into the net cups that are snugly fit inside the lid. The roots will reach out into the nutrient solution available below. 

Since hydroponic systems need both oxygen and water to grow plants, leaving a small gap of air in the reservoir is essential. This small air gap between the lid and the solution will provide ample oxygen for the roots, which is why you don’t even require an air stone. 

As days pass by, you will notice that the roots begin growing down towards the solution. On the other hand, the solution will reduce slowly as the plant takes up the nutrients. As long as you ensure that you keep topping up the solution, the system will work perfectly. 

2. Deep Water Culture


Deep Water Culture consists of a reservoir holding large volumes of water, and the plant roots are submerged in the reservoir. This setup helps you grow cannabis plants faster, and the best part is that it’s pretty easy to maintain — perfect for newbie cannabis growers.

Unlike other techniques where the plant roots hang in the air, the plants will be submerged in the water in DWC. Of course, the water needs to contain enough oxygen to support the plants. Since the roots are deep in the nutrient solution at all times, this technique is named Deep Water Culture. Sometimes, it's also called Direct Water Culture.

In DWC setups, the size of the reservoir plays a crucial role in growing plants. The bigger the reservoir, the more water it holds, which means less maintenance. If the reservoir is small, you will need to top up the solution constantly.

Many growers hesitate to use the DWC system because the roots are always submerged in water — it’s natural to assume that water can suffocate the plants. While it's true that the plant roots can rot if you submerge them in water 24/7, this theory doesn't hold for DWC systems, or any other hydroponic systems, for that matter.

Keep in mind that although the plant roots are in the water, they will also contain oxygen. In addition, the grower will take care to place the setup in an environment with optimal temperatures, lights, and nutrients.

So, how do you provide oxygen in this setup? As you can see in the image above, you will need an air pump that generates plenty of bubbles. Since the plant roots have access to oxygen and nutrients at all times, they are likely to grow better than plants grown in soil.

Remember that the system will work perfectly only if you keep the air stone and air pump running at all times. Check your equipment regularly as the plants will start suffering immediately if the air stone or air pump stops working.

3. Ebb and Flow System

Ebb and Flow

The Ebb and Flow system is slightly more complex, but it is pretty versatile and allows you to grow several plants in one go. 

Ebb and Flow is one of the most effective hydroponic methods to grow cannabis. Although it does take some effort to set this up, the plants grow flawlessly once you are done. Also known as the flood and drain system, the Ebb and Flow system involves regular flooding and draining of nutrient solutions.

This system works by growing the plants in a coarse medium, like clay pellets, allowing plenty of space and oxygen. The system floods the medium with nutrient solution for a few minutes and then drains it back into the reservoir located under the medium tray.

This technique saturates the medium with nutrient-rich water, allowing better growth and yield. However, since this process is time-sensitive, we recommend using an automated flooding mechanism to feed the roots on time. 

Essentially, there are two stages of the Ebb and Flow operation. The first stage is the flooding stage, where the nutrient solution flows over the roots. The second stage is the draining stage, where the water drains into the reservoir. Since both operations occur simultaneously, it is called the Ebb and flow system.

Typically, you can use several containers or one single container and arrange the plants on them. You will need a timer to control the water. Once the pump starts pumping the nutrient solution, it flows into the growing tray and soaks all the plant roots. 

As soon as the limit is reached, the overflow tube takes over to maintain the standard level. The tube also prevents the nutrient solution from spilling out. The pump stops once you switch off the timer, and the nutrient solution is drained back to the reservoir. Most growers use the overflow tube to pump oxygen into the reservoir; however, you can use an air pump to do the same. 

4. Nutrient Film Technique


You don’t need growing mediums if you use the Nutrient Film Technique. Instead, the roots are suspended in the growing tray. The system constantly passes fast-flowing aerated nutrient solution through the growing tray, enabling continual nourishment and oxygen.

The suspended roots get to absorb nutrients through the water without your intervention. So, this technique is ideal for large-scale cannabis cultures!

NFT works like Ebb and Flow since both systems rely on water pumps while delivering the nutrient solution to plants. But the main difference is that while Ebb and Flow works by flooding and draining mechanisms, the water is constant in NFT.

To build an NFT system, you will need a reservoir, a nutrient pump, a few tubes that will distribute water from the pump to the tubes, a channel to grow the plants, a few net pots, and a return system that allows the nutrient solution into the reservoir.

The channel or the growing tray and the reservoir are two primary components in this system. To grow the plants, fill the net pots with your preferred growing media to hold the plants and reserve some nutrients from the solution. 

Many cultivators prefer not to use growing media since the roots get ample moisture, oxygen, and nutrients through the system itself. You will need a pump that delivers water to the tray and a pipe that helps recycle any unused water.

As you can see in the image, the growing tray sits at an angle, and you can support it with a rack. The design is such that it allows the water to flow to the return pipe. Any excess solution flows out and moves to another channel so it can be recirculated.

The nutrient solution will have a film on top of it. The plant roots touch the film and absorb the nutrients. This design allows the plant roots to absorb as many nutrients as possible without getting soaked in the process.

5. Aeroponics System


Aeroponics is another technique to grow plants. Here, the plant roots hang free, and sophisticated misters spray the roots with nutrient-rich water solution every few minutes.

The aeroponic system is an excellent way to grow cannabis. It helps the roots absorb oxygen and nutrients quickly by misting, leading to plants that grow bigger, fatter, and healthier. The only downside? It requires expensive pumps and misters, which might not be affordable for most new cannabis growers.

Aeroponics works just like the hydroponic system; however, the primary difference is that while hydroponics utilizes water as the medium, aeroponics does not require any medium at all.

For example, in hydroponics, plants are usually inserted in growing media like perlite or hydroton, but the plant roots are suspended in growing chambers in closed-loop mechanisms with aeroponics. The nutrient solution is periodically sprayed onto the plant roots to help the plants grow.

Currently, aeroponics is one of the most advanced systems to grow any plant, including cannabis. Like hydroponics, the nutrients are delivered directly to the roots.

Comparing hydroponics and aeroponics, plants grown in the aeroponics system tend to grow fast and healthy because they get to absorb oxygen in abundance. In addition, root zone diseases are unlikely because the debris has no space to collect in this system. However, there is a chance for fungi and other bacteria to develop much more than other systems because the roots are wet at all times.

To grow plants using the aeroponics technique, you must place the reservoir inside a sealed container. Then, you can insert the plants through holes at the top. Since the plants need an anchor, you will have to customize a support collar to hold them in place. Make sure the collars are rigid yet flexible for the plant to develop more roots.

You'll also need a timer to supply the nutrient solution at periodic intervals. Due to excess oxygen, the plant roots will develop faster than any other technique.

Summary: 5 Techniques To Grow Cannabis Hydroponically

You can now grow healthier and more potent cannabis without creating a mess in your basement, no matter what method you choose among the ones described above. If you’re a beginner, choosing a passive hydroponic system may work for you because they are inexpensive and don’t require additional electricity. 

On the other hand, if you have some expertise or want to cultivate cannabis commercially, you can go for active systems. That said, even beginners can use active systems as long as they understand the science behind it all. Once you grow a few plants, it becomes effortless to continue with the same setup and tweak it according to your requirements. 

You can also start with passive systems and switch to active systems once you’re comfortable. Simply put, choose a system that works in the long run. Figuring out the proper method may take some time, but once you get the hang of it, you will be on your way to becoming a pro at growing cannabis hydroponically.



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Hi, great article! I wanted to ask, I use a DWC and I notice that when I fill the water up the max, meaning the water to reach the bottom of the plastic holder, my plants consume water at a lower pace. So I always like to leave 5cm (2inch) of space at least. I have a good pump and a rather good size air stone. So my question is, how much oxygen does one need to pump in order for a total submersion not to have adverse results? Best Regards, NoobSquad
Hi there, Very interesting, i will upload my personnal ebb and flow (flood and drain) auto syphon growbed setup soon 😎, yeah hydroponic became bazooka, Best Regards Crew