Continuous Flow Hydroponic Systems for Cannabis — A Detailed Guide

The journey of a cannabis grower is always about growth — finding innovative ways to evolve as a grower and improve the growth setup. In this journey, many cannabis growers start from simple pots and eventually grow into basic hydroponic systems.

This is where many growers stop evolving, but if you want to grow further, one of the natural steps is choosing a continuous flow hydroponic system for your future cultivation. 

A continuous flow hydroponic system uses an array of pumps, pipes, and air stones to continually supply the roots with nutrients and oxygen in a meticulously controlled environment, leading to terrific results. 

But what is a continuous flow hydroponic system for cannabis, and how does it fit into your grow room? Learn everything you need to know about continuous flow hydroponic systems for cannabis in this article.

What is a Continuous Flow Hydroponic System for Cannabis?

As the name suggests, a continuous flow system is a type of hydroponic setup that continuously exposes the cannabis roots to the nutrient solution. And just like other hydroponic setups, a continuous flow system for cannabis does not use soil at all; the nutrient solution contains all the minerals and nutrients required for the plant to grow well. 

The primary difference between a continuous flow system and other hydroponic setups is that the latter does not expose the roots to a constant flow of nutrients. In a continuous flow system, the roots are fed with a steady supply of nutrients and oxygen, which leads to much better results. 

What are these results? Thanks to a continuous flow hydroponic system, you can grow cannabis plants that grow fast and yield terrific buds. This is because optimal levels of nutrients and oxygen are supplied to the roots continuously, leading to much better root development and nutrient absorption. 

A continuous flow hydroponic isn't a single system. Instead, it is a group of hydroponic systems. These systems share a core concept but differ drastically in how they function. For example, some continuous flow systems supply water continuously from the reservoir while others use a different method of administering nutrients, such as from fish poop or mist sprays. 

But despite their differences, all continuous flow hydroponic systems for cannabis work on a single concept — providing water and nutrients to the plant's roots, capturing the runoff water, and recycling it back into the system. The benefit of this system is that your hydroponic system will use 10x less water than other soil-based methods. 

To make this all happen, a continuous flow hydroponic system uses a few crucial tools or devices, such as the following.

1. Nutrient Reservoir

The most crucial part of any continuous flow hydroponic system is the reservoir. This external unit holds the nutrient solution containing all the minerals and nutrients required for a healthy plant to grow. 

2. Plant Tray or Channels

The next most important part of this setup is a plant tray or channel, which holds the plant itself while providing a passage for the nutrient water. These trays come in all shapes and sizes, and you can choose one that fits your plant and preferences.

3. Air Stone

An air stone — similar to the one used in a fish tank — is also used in a continuous flow hydroponic system to pump oxygen into the nutrient solution. Therefore, it's placed in the nutrient reservoir to aerate the solution, making it possible for the roots to respire despite being in water continuously.

4. Net Pots

On the plant trays sit net pots, which hold the cannabis plants in place. Apart from holding the plant upright, net pots also ensure the roots grow in the right direction, i.e., into the tray under them.

5. Other Hydroponic Peripherals

Other peripherals remain the same as any other hydroponic setup. So, even with a continuous flow system, you'd still need equipment, including grow lights, fans, exhaust, carbon scrubbers, humidifiers/dehumidifiers, an air conditioner, etc. 

The only thing that changes with a continuous flow system is the way the nutrients are delivered to the roots — most other things remain the same. 

What are the Advantages of Continuous Flow Hydroponic Systems?

Continuous flow hydroponic systems offer many benefits that other growing systems do not, especially soil-based ones. What are these? Here are some of the benefits of a continuous flow hydroponic system for cannabis.

• Much Better Yields

One of the first advantages of a continuous flow hydroponic system is better yields. Since your cannabis plant will grow in a continuous flow of nutrient- and oxygen-rich solutions, the roots will grow a lot bigger and consume more nutrients. At the same time, this setup reduces the risk of pathogens and pests. So, your plant will be able to grow bigger, better buds.

• Faster Life Cycle 

In soil, the roots must look for nutrients and establish a relationship with the microbes for many minerals. But in a continuous flow hydroponic system, the roots don't have to do the hard work — the system does it for them. 

Due to this easy accessibility of nutrients and minerals in a continuous flow hydroponic system, the plant can grow and mature faster, leading to a much faster life cycle. 

• Increased Oxygenation of the Roots

Cannabis roots require a lot of oxygen to respire, which makes many physiological processes possible. But when the roots can't get enough oxygen, their function can be hampered and even become prone to pathogen attacks. Thanks to the continuous flow of aerated solution in this setup, the roots never run out of oxygen and suffer from this risk. 

• More Eco-friendly

Since hydroponic systems run entirely on water, many people believe they use more water and are bad for the environment. That's far from the truth. Hydroponic systems are inherently more eco-friendly since they use 10x less water than soil-based plants. 

Additionally, continuous flow hydroponic systems use reservoirs and pumps to recycle water continuously to minimize water wastage. 

What are the Drawbacks of Continuous Flow Hydroponic Systems?

Despite some attractive advantages, continuous flow hydroponic systems have some drawbacks that can't be overlooked. While most of the drawbacks aren't dealbreakers, it is better to keep them in mind when choosing this system so you know what to expect and how to prepare for it.

Here are some of the common drawbacks of continuous flow hydroponic systems for cannabis.

• Uses a Lot of Energy

Continuous flow hydroponic system is eco-friendly because it uses a lot less water than traditional growing systems, but this benefit is somewhat compromised due to its energy consumption. 

Continuous flow systems use water pumps and air stones at all times, which can rake up your energy bills. The only way to avoid this is by investing in solar panels.

• Needs Some Upkeep

Even though you don't have to worry about maintaining rich soil or other problems with soil-based systems, continuous flow hydroponic systems come with their requirements, one of which is constant maintenance. 

An ideal continuous flow hydroponic system uses various components, many of which are constantly in touch with water, so you need to ensure they are always clean to prevent algae or mold buildup. You must also maintain every nook and cranny of the system to prevent leaks or other problems.

• Less Forgiving for New Growers

Murphy's Law applies here, too, and when things go wrong, they can go wrong drastically. For example, failed pumps, power cuts, clogs, etc. can cause severe problems for your plant, and if you don't take immediate action, they can affect your plant's health quickly. 

What are the Types of Continuous Flow Hydroponic Systems?

As mentioned earlier, there are many types of continuous flow hydroponic systems, and choosing one may be confusing. To help clear this confusion, here are the common forms of continuous flow hydroponic systems with their benefits and drawbacks.

1. Nutrient Film Technique (NFT)

The nutrient film technique uses narrow, long growing channels that are positioned at an incline, and the net pots are positioned into these channels. The nutrient solution is directed throughout the day through these channels to feed the roots. 

Since the roots also require a lot of oxygen for respiration, NFT makes this happen by permanently exposing most of the root mass to air while a thin film of the nutrient solution is circulated through the channels. 

Despite being shallow, the nutrient supply contains all the necessary nutrients and minerals your plant requires to grow well, and the aerated mass of roots gets to enjoy high levels of oxygen all the time. 

This is why NFT has many benefits, the first of which is its effect on your plant's growth. With NFT, you can meticulously control your plant's growth and give it the right nutrients, which leads to a much healthier plant and improved yields during harvest. 

Additionally, this continuous flow system is simple to set up and maintain. And it is quite modular, too, so you can stack multiple trays to maximize your space. NFT also allows you to control the feeding regimen meticulously, so your plant gets exactly what it wants and this also translates to improved water efficiency and less wastage. 

But the nutrient film technique is not completely free of problems. A simple power cut can ruin the entire setup and potentially kill your plant! You need to maintain the right balance between nutrients, water, air, and other environmental factors for healthy plant growth. This makes this system less forgiving for new growers, which is why we only recommend it to experienced hydroponic growers. 

Advantages:

• Water and nutrient conservation: NFT recirculates water and nutrients, reducing the overall amount of water and nutrients required for the plants to grow.
• Increased oxygenation: The roots are continuously exposed to oxygen, which can result in faster and healthier growth.
• Space-saving: NFT is a relatively compact growing method, as the plants are grown in channels rather than individual pots or containers, which can be beneficial for those with limited space.
• High yields: NFT can result in higher yields, as plants can receive a constant supply of water and nutrients, allowing them to grow more efficiently.

Disadvantages:

• Potential for plant stress: Since the roots are constantly exposed to air and light, they may dry out or become stressed if there is a problem with the nutrient solution flow or a power outage.
• Technical expertise required: Setting up and maintaining an NFT system requires technical expertise and attention to detail, such as ensuring the proper nutrient solution pH and flow rate.
• Risk of disease: NFT systems can be susceptible to root diseases, especially if the water is not oxygenated correctly or if the plants are overcrowded.
• No backup system: Unlike other hydroponic systems, NFT has no backup system to keep the plants alive in case of a pump failure or other technical malfunction.

2. Aquaponics

One of the weirdest ways to grow cannabis is to use fish poop. Enter aquaponics — an innovative hydroponic system to grow cannabis (and many other) plants, and this system uses fish as the primary source of nutrition for the plant. 

Essentially, aquaponics can be used with NFT or drip irrigation, but it differs from those systems in the reservoir department. Unlike other systems where the reservoir is just a water tank, the aquaponics reservoir is a fish tank. 

So, instead of constantly mixing nutrients to create the nutrient solution, you simply need to raise fish in the reservoir, which will produce nutrient-rich poop daily — enough to sustain a healthy cannabis plant!

Not only that, but the plant's roots also keep the water clean so that the fish can live a healthy, clean life under your cannabis plant. Perfect if you love fish and cannabis!

One primary benefit of aquaponics for growing cannabis is a quick turnout. Thanks to the nutrient-rich feeding regimen, growers claim their plants grow faster and are usually ready for harvest at least ten days prior compared to other growing methods. And despite the quick turnaround time, the yield is still terrific. 

Additionally, aquaponics saves a lot of water. Cannabis, after all, is a thirsty plant. Since the fish and the plant maintain an almost symbiotic relationship, the water stays clean. It is constantly fed with nutrients, so you don't need to replace the water as frequently as you would have with other hydroponic systems. 

And this benefit only gets better the more organic you get with your aquaponics setup. 

But before you jump into building an aquaponics system of your own, you need to consider the drawbacks of this system. One of which is its setup and maintenance costs. Aquaponics is expensive to set up and run since you need many fish, bigger pumps, a large fish tank, and some other specific equipment pieces. 

You must also manage the needs of both the plant and the fish simultaneously. Ignore one and the other will suffer the consequences. And maintaining fish is more challenging than maintaining plants. They need to be taken care of, and if you're growing long-flowering strains, you may need to cycle your fish twice during a single growing cycle. 

So, you should only pick this form of continuous flow hydroponic system if you are okay with taking more effort. But once you manage to get a knack for aquaponics, you will reach a level few hydroponic growers get to — that is rewarding and worth it, even if it's just for internet brownie points.

Advantages

• Efficient use of resources: Aquaponics uses significantly less water than traditional soil-based agriculture and eliminates the need for chemical fertilizers.
• High yields: Aquaponic systems can produce high yields of crops in a relatively small amount of space, making it an attractive option for urban farming and small-scale agriculture.
• Low maintenance: Once established, aquaponic systems are relatively low maintenance and can be easily automated with timers and sensors.

Disadvantages

• Initial investment: Setting up an aquaponic system can be expensive due to the need for specialized equipment and infrastructure, such as fish tanks and water pumps.
• Technical knowledge: Aquaponics requires a certain level of technical knowledge and expertise in areas such as maintaining a fish tank, water chemistry, and hydroponics. 
• Risk of system failure: Aquaponic systems are vulnerable to power outages, equipment failures, and other malfunctions that can disrupt the delicate balance of the system and cause losses.
• Limited crop selection: Some crops are better suited for aquaponic systems than others. However, cannabis is a great candidate for aquaponics, so this isn't a significant disadvantage. 

3. Aeroponics

If you think aquaponics is as good as it gets, there's one system that one-ups it — aeroponics — a type of hydroponic system used by NASA to grow plants in space! 

This type of continuous flow system consists of a growing chamber made of PVC pipes or similar products, with net pots inserted into the pipes. The roots are left suspended in the air within the chamber. 

A mister then delivers a cloud of nutrient solution to the roots regularly, which is then collected at the bottom and rerouted to the reservoir for future use. As a result, this form of a continuous flow system is very efficient in its water usage and compact and discreet in terms of its design.

Another benefit of aeroponics is that regular misting ensures the roots don't develop root rot and are always aerated while reducing evaporation and saving electricity. All these benefits come together to make aeroponic cannabis perform way better than most other types of cannabis grow systems. 

But despite the benefits, aeroponics isn't recommended for beginners. While the system looks simple enough, it is difficult to maintain and requires the use of somewhat expensive devices, like automated misters.

Advantages

• Increased oxygenation: High levels of oxygen in the root zone promotes fast growth and nutrient absorption.
• Efficient nutrient use: Aeroponics allows for precise nutrient delivery, resulting in efficient use of fertilizers.
• Faster growth rates: Plants in aeroponic systems can grow up to 50% faster than plants grown in soil due to increased oxygen and nutrient availability.
• Space-saving design: Aeroponic systems require less space than traditional soil-based growing methods, making them ideal for indoor growing.

Disadvantages

• High maintenance: Aeroponic systems require regular maintenance and monitoring to ensure proper nutrient delivery and prevent clogging of misting nozzles.
• Prone to power outages: Aeroponic systems rely on electricity to pump and mist nutrient solution, so power outages can be detrimental to plant health.
• Susceptible to pathogens: The exposed roots in aeroponic systems can be vulnerable to pathogens and disease if not properly monitored and treated.
• Costly setup: The equipment and materials needed for an aeroponic system can be expensive, making it a less accessible option for some growers.

4. Drip Irrigation 

Drip irrigation is one of the most common forms of hydroponic setups used for cannabis cultivation, and this system consists of a regulated flow of nutrient solution that is top-fed to the plant. 

Since the feeding regimen is finely controlled, drip irrigation is more efficient, ensuring the least amount of water wastage. Apart from that, drip irrigation systems are also relatively low maintenance since they only have a few moving parts. The simple architecture of drip irrigation also makes it cheap to build, making this system perfect for new growers. 

Advantages 

• Precise water delivery: Drip irrigation allows for accurate delivery of water and nutrients to the plant roots, reducing the risk of over- or under-watering.
• Water conservation: Drip irrigation uses less water than other methods, making it a more environmentally friendly option.
• Reduced weed growth: Since water is only delivered to the plant roots, there is less moisture on the soil surface, reducing the growth of weeds.
• Scalability: Drip irrigation systems can be scaled up or down to fit the size of the growing operation.

Disadvantages

• Clogging: Drip irrigation systems are prone to clogging if you don't maintain them properly.
• Soil nutrient concentration: Drip irrigation can concentrate the nutrients in one area, leading to uneven plant growth if not properly managed.

What to Consider When Purchasing a Continuous Flow Hydroponic System?

Continuous flow hydroponic systems are a broad concept, and choosing the right setup for yourself can be a bit confusing. To make things easier, you should consider a few things when choosing the right setup for you, which are as follows.

• Noise

One of the first things you must consider is the noise the system will create. Continuous flow systems consist of water pumps and air stones, which can generate some sound. So, you must ensure that these devices are quiet enough to not bother you when they are operating. 

• Modularity

The next thing you must consider is how modular the system is so you can expand your growth in the future by adding new troughs. Adding a new module is always easier than revamping the entire system! 

• Size

Size is another important consideration when choosing a continuous flow hydroponic system. For instance, aeroponics is compact and can be used with limited space. Figure out how much space your cannabis plant needs and add a bit of extra room, just in case. 

• Budget

Hydroponic systems aren't cheap in the first place, and continuous flow ones can get even more expensive. Systems like aeroponics or aquaponics are some of the most expensive growth setups for cannabis. So, figure out how much your budget is and choose a system that fits.

• Ease of Use

Lastly, you must keep the ease of use in mind. If you are a relatively new grower, choosing a system like aeroponics or NFT wouldn't be the best choice for you — such systems require constant monitoring and maintenance and are less forgiving of errors. 

So, depending on your skill set, you should choose a continuous flow system that is easy for you to manage. Remember, growing cannabis is supposed to be fun first and challenging second. 

Can You Build Your Own Continuous Flow System?

What if you don't want to purchase a continuous flow system and rather build your own — can you do it? Of course, you can! The continuous flow system is a broad term encompassing many growth systems. 

Many of these systems can be DIY-ed easily, which is a fun experience and can save you a lot of money in the long run. Even the more complex systems, like NFT or aquaponics, can be built at home as long as you get a little creative and use some elbow grease. 

If you want to go that route, we recommend you read our guides on each of these systems above. We have added links to help. In addition, you can talk to other growers and use their ideas as inspiration. It only looks daunting if you don't know what you need to do. 

Summary: Continuous Flow Hydroponic Systems for Cannabis — A Detailed Guide

A continuous flow hydroponic system is an excellent way to take your cannabis cultivation up a notch and produce much better yields from your plants. This system supplies nutrients to the roots along with oxygen, leading to better root development.

And healthy roots translate to a healthy plant. Also, meticulous control ensures the plant grows in a safe, healthy environment with many risks of pests or pathogens. The result is a bigger plant with even bigger yields. 

One benefit that makes this system stand out from the rest is how eco-friendly it is. Since the water is constantly recycled in a closed-loop system, the continuous flow system uses ten times less water than other forms of cannabis cultivation methods. 

Choose the right type of continuous flow system, though. The most popular options are nutrient film technique, aquaponics, aeroponics, and drip irrigation — choose one that fits your preferences the best. 

But remember to factor in things like noise, modularity, budget, size, and ease of use and maintenance when choosing the right setup for you. And if you want to save some more money or want to work on an interesting project, you can always DIY your continuous flow hydroponic system at home. 

But whichever method you use, remember to always do adequate research before making any decision.