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What Is Hydroponic Weed? How To Grow Cannabis In A Hydro System

hydroponic cannabis

To the uninitiated, hydroponic weed and the systems used to produce those dank, resin-covered water-grown buds can seem a little daunting. 

More akin to something out of a research facility than a setup you could get going easily in your own home. But, with just a little bit of knowledge and passion – and the correct equipment – hydroponic weed cultivation is a super interesting and rewarding way to get your green fix, and not as complex as some may make it out to be.

Once you get used to this style of cultivation, it can actually make your growing routine less complicated (when compared to organic cultivation – especially for larger scale operations) thanks to just how easy it is to automate a bunch of the processes in hydro setups. And then there is the boost in both potency and yield that goes hand in hand with soil-less cannabis gardening.

With a huge range of options on the table for hydro growers and an even bigger variety of top-shelf cannabis strains that work unbelievably well with hydroponic cannabis cultivation now on offer, there has never been a better time to get it cranking. Let’s get straight into it!

What is Hydroponic Weed?

It’s pretty safe to say that most cannabis users have heard of hydroponic weed, but not all of them understand what it actually refers to. While the knowledge base of the everyday stoner has increased tenfold over the last decade or so (thanks mostly to recreational legalization finally coming into effect in a bunch of states and countries), there is still a large chunk of the weed-enjoying population that is mystified by hydroponics in general, and hydroponically grown weed more specifically.

So, what is hydroponic cannabis exactly?

In a nutshell, hydroponic weed is cannabis grown without soil as the main medium. Instead, the cannabis plants are supported and fed by a nutrient-rich solution applied directly to the root system, in place of the roots feeding on the nutrients naturally found in living soil. Rather than the roots developing throughout and being supported by the soil, hydro systems use a wide range of inert materials (i.e clay balls, Rockwool, vermiculite, etc.) to support the root system of the plants – or even no root support at all, but we will get more in-depth with this later.

This nutrient solution feeding system allows the cultivator to have way more control over the exact levels of each specific nutrient that the plant receives, and so the nutrient concentration can be tailored to the stage of growth, and the specific needs of the strain being grown. This level of control can result in faster growth rates, higher cannabinoid percentages, and a more predictable yield. Easy to see why hydroponic cannabis cultivation has become so popular over the last couple of decades, yeah?

What are the Different Kinds of Hydroponic Grow Systems?

In this brave new world of cannabis legality, the range of hydroponic systems available for cultivators at all levels of expertise expands yearly. New designs are constantly being developed, and updated versions of older systems are brought out to the market to cater to the ever-changing needs of industry professionals and home growers alike.

Small Hydro System Cannabis
Cannabis seedlings growing in a hydro system.

There are a handful of these systems that have become the industry standard and are used by both hobby home growers and commercial cultivators. But, before we run through the most common hydroponic weed systems, there’s one thing we have to clarify – the difference between passive and active hydroponic cannabis cultivation systems.

Passive Hydroponic Systems

Passive hydroponic systems are the more simple of the two and rely on either gravity, the capillary action of the roots, or separate wicks to deliver the nutrient solution.

Active Hydroponic Systems

Active hydroponic systems are somewhat more complex and are more commonly used by commercial cannabis growers (or home cultivators that have previous growing experience) due to the higher degree of control that they offer. These systems use pumps to deliver the nutrient solution to the roots and can be easily automated.

Ok, now that we have that out of the way, let’s take a look at the best hydroponic weed systems.

The Kratky Method

Using The Kratky Method is the simplest of all passive systems and is also one of the easiest methods for beginners to get to grips with. However, The Kratky Method uses no pumps, timers, or monitors, and relies solely on the plant’s natural capillary action to suck up the nutrients it needs from the reservoir.

The Kratky method can be set up with a wide range of materials, but in its most basic form it involves suspending a net cup filled with an inert medium – usually clay balls – above the nutrient reservoir. This allows the upper roots to sit in the gap above the nutrient solution and receive oxygenation, while the lower roots reach down and essentially ‘suck’ up the nutrient solution.

The Wick System

The Wick System is another form of passive hydroponics and works in a very similar way to the Kratky method. The only real difference is that instead of the roots being in direct contact with the nutrient solution, a wick is used to transport the nutrient solution from the reservoir up to the roots. This wick must be kept in contact with the nutrient solution at all times otherwise the crop will quickly dry out.

Drip System or Top Feed System

The drip system (also known as a top feed system) is one of the most common and widely used hydroponic weed grow systems, and for good reason. Not only is it extremely simple to set up, but it’s also incredibly reliable once running – making it a great system for both indoor and outdoor cultivation.

Drip systems are a form of active hydroponics. It works by the solution being pumped from a reservoir to the plants through small water lines connected to a timer – which allows you to set the frequency, duration, and amount of nutrient solution delivered to your crop. The drippers are placed

The Ebb and Flow System (aka Flood and Drain)

Another hugely popular hydroponic cannabis cultivation system is the Ebb & Flow system. Also known as a flood & drain system, the ebb & flow works again with the crop suspended in grow nets that are usually filled with an inert medium to help support the roots and the plant itself. These sit above a grow tray that has a water inlet and outlet which are both connected to a separate nutrient reservoir. This res will also hold an air stone to oxygenate the feeding solution and a pump to flood the growing tray.

With this system, the grow tray is flooded (at regular intervals) with the oxygenated nutrient solution. The pump pushes the solution into the grow tray area, and once the pump is deactivated the grow tray drains back to the reservoir.

Deep Water Culture

Deep Water Culture (DWC) is an active version of the Kratky system. The one main differentiating factor is that rather than having the plants sitting above the water-filled res with an air gap to provide root oxygenation, the entire root system is in contact with the nutrient solution.

Deep water culture cannabis

The water is instead oxygenated by an air stone and pump that deliver bubbles to the root zone of each hydroponic weed plant.

Nutrient Film Technique

The Nutrient Film Technique is a very similar setup to the Ebb and Flow system but in place of the grow tray being flooded periodically, the tray instead sits at a slight downward angle which allows a fresh stream of the nutrient solution to be in constant contact with the roots. The inlet is placed at the higher end of the grow tray, which allows the solution to flow through the roots, and then to the outlet which returns it to the reservoir.

The res holds an airstone for oxygenation, and a pump to move the water through the system.


Aeroponics is one of the more complicated systems to set up and maintain, but the results (when implemented correctly) are pretty fantastic.

Aeroponic Cannabis

Aeroponically grown weed is exposed to optimal levels of root zone hydration and oxygenation through a system of misters that spray the nutrient solution directly at the roots. The roots are suspended in grow nets and exposed to the mist at regular intervals, which encourages rapid growth. The nutrient solution is held in a separate reservoir where it’s constantly oxygenated.


Bubbleponics, similar to Aeroponics, is at the cutting edge of hydroponic weed cultivation. It works by having the roots suspended in a grow net and immersed in an oxygen-rich nutrient solution held in a separate reservoir. A pump then delivers the nutrient solution to the grow tray, and a separate pump provides bubbles of air to the root zone, allowing for optimal oxygenation, hydration, and growth.

Cannabis plant growing in bubbleponics

The difference between Bubbleponics, DWC (Deep Water Culture), and Aeroponics is that Bubbleponics offers the best of both worlds. The roots are exposed to oxygen-rich bubbles and continuously submerged in a nutrient solution, sometimes with a drip feeding system also combined to boost nutrient cover to the root ball.

What Are The Best Mediums Available For Hydroponic Weed?

A common question posed by novice growers is – What is a hydroponic medium?

In the simplest of definitions, Hydroponic media refers to any material used to support and nourish the roots of your plants. In hydroponic systems, this material replaces soil and provides a base for the roots to attach themselves to.

Choosing the right medium for your hydroponic cannabis garden can make or break when it comes to setting up your system, and the health and success of your grow. You need to make sure you choose a medium that fits with the type of hydroponic system you are using, and that provides your plants with the best support, drainage, and air/water retention.


Rockwool is one of the most commonly used mediums for hydroponically grown cannabis, and for good reason. It is able to hold high levels of oxygen while saturated, and because it is a non-degradable material, you can reuse it season after season. It is also widely available and easy to work with.

Expanded Clay Balls

Expanded Clay Balls are another very often used medium.  Clay balls are capable of holding a lot of moisture and oxygen, while also being lightweight and easy to work with. They are also known as either hydroclay or hydroton, and feature a small hole through each ball that allows the nutrient solution and oxygen to pass through, as well as acting as an anchor point for the roots.

The only slight downside is that clay balls are not as durable as some of the other medium options and can break down over time – but honestly, at that point, you would probably be looking to replace them either way, so no real drama there.


While Perlite can be successfully used as a stand-alone hydroponic medium, it does break down pretty quickly. It is essentially lightweight volcanic glass, and while it makes a fantastic addition to other mediums (like coco coir or soil), it is not generally used as the sole material.

This is because it does not hold water and nutrients very well, and it’s hard to sterilize to a satisfactory level between grows.


Vermiculite is a naturally occurring material that is great for rooting clones, but not usually recommended as a primary medium for hydroponic cannabis. It retains water very well but does not offer much in terms of drainage or oxygenation.


This may seem a little counterintuitive, but air can actually make a really great medium. While roots need a nutrient solution to feed from and moisture to survive, oxygenation of the roots is just as important. As long as the roots are kept in a humidity-rich environment and misted with the feed water, systems that utilize air as the medium can be extremely successful.

Hydroponic Weed  – Frequently Asked Questions

Right, we have run through the most commonly used hydroponic cannabis systems and medium options, but no doubt you still have some lingering queries. Let’s run through the most commonly asked questions about hydroponics and growing weed.

Should I Jump Straight Into Cannabis Hydroponics?

Look, for sure you can, but we don’t generally recommend it.

Cannabis cultivation is complex, and the hydroponic system adds a whole extra layer of complexity. It is usually worth starting out with a simpler method like soil or coco-coir before diving headfirst into the hydro biz, but that doesn’t mean you can’t be super successful straight up.

Small Hydro System Cannabis
Cannabis seedlings growing in a hydro system.

There are tons of growers out there who have tried hydroponic weed cultivation, and in the long run, decided it wasn’t for them. Besides, there are advantages of growing with both organic methods or coco-coir as the main substrate.

What Is The Best Hydro System For Hobby/Home Growers Starting Out?

This really depends on your budget, the size of the growing area, and your growing experience. Generally speaking, DWC systems are great for starters as they are relatively simple and don’t require a bunch of expertise or fancy equipment.

However, if you have a bit of extra cash to spend or want to experiment with a more complex hydro system, then you have a whole range of options. If you are starting from scratch, then it might be wise to invest in an all-in-one system, like the grow box or tent packages that are widely available.

These often come with everything you need to get started right away, including the medium, the pump, and other key pieces of hardware — all you need to do is provide the seeds and nutrients.

Which Company Produces The Best Nutrients For Hydro Weed?

There are literally hundreds of hydroponic nutrient brands on the market, all claiming to be the best choice for hydroponic weed. As a general rule, it is wise to stick with established, reputable brands. FoxFarm, Advanced Nutrients, General Hydroponics, Botanicare, Dyna-Gro, and Canna are all great choices, but that’s not to say that there aren’t a bunch of other top-class options out there.

If you live in an area with easy access to hydroponic suppliers, head on in and see what they have on offer. More often than not there will be a few locally produced brands that are a little cheaper than the big names but still do a great job.

Also, make sure to pay attention to the specific nutrient ratios and water pH levels. Getting both of these right is essential when it comes to hydroponic cultivation.

One last thing. Nutrient companies are businesses, and what do businesses exist for? To make money. Nutrient brands make cash by selling more nutrients, so you can’t always trust the exact instructions provided on the bottle as they can, oftentimes, be at least slightly inflated.

Best to start with a quarter dose, especially for seeds that have just recently germinated.

How Do I Make Sure The Dosage And pH Levels Are Perfect?

You going to have to invest in both an EC (or TDS) and a pH meter. pH meters are pretty cheap, but you’re not going to want to skimp on the EC meter.

The perfect pH range for hydroponically grown cannabis is 5.8 to 6.2 – you can float slightly outside these numbers and still be fine, but it’s best to stick as close as possible. The EC (Electrical Conductivitey) or nutrient dosage level will increase as the plants develop, and the ratios needed will vary depending on the stage of growth.

It’s also worth noting that different strains will need different EC levels for optimal growth, and can become stunted if they are subjected to nutrient levels that are too high or too low. The best way to avoid this is to start with lower EC levels and slowly ramp up as the plants get bigger and their nutritional needs increase.

How Much Does Setting Up A Hydroponic Cannabis System Cost?

This is probably the most commonly asked question, and definitely, the hardest to answer. It really depends on the type of system you want to set up, how many plants you plan on growing, the size of the grow area, the quality of the equipment, and how much work you are willing to put into setting up the whole thing up.

At its simplest, you can put together a basic flood and drain (ebb and flow) system for as little as $100.

If you have a bigger budget, then you can always choose from a range of more expensive, and often better quality, equipment.  Around $400 should be enough to get you set up a decent home system for multiple plants but for in-depth answers to this question it’s best to check out our specific blog posts for each hydroponic system.

What Are The Main Advantages Of Growing Weed Hydroponically?

The list of advantages to hydroponic cultivation is pretty extensive.

Hydroponic systems are incredibly efficient and can produce a tremendously high yield of top-shelf, dense, frosty stickiest of the icky possible. 

Hydro systems – when run correctly – also reduce the chance of pests and diseases, boost potency to the very peak possible, shorten grow cycles (which means you can have multiple harvests in the same year), and conserve water by recycling it through the system. They also make it easier to control the environment, and the cleanliness of the grow room or tent. It’s much easier to access the roots of hydroponically grown cannabis, which allows for easier root trimming and inspection.

Are There Any Disadvantages?

Yep, but the severity of these downsides doesn’t outweigh the positives of hydroponic growing. One of the major cons is that, if you are new to hydro systems, you’ll need to learn how to use them adequately. They can, depending on the system, require a decent amount of knowledge and experience to get the most out of them, but this learning experience is all part of the fun.

Many experienced growers believe that organically, soil-grown bud has a rich and deeper terpene and flavonoid profile than hydro weed, and while there isn’t any real science to back this claim up, we do tend to agree.

Hydro weed will still taste and smell amazing, but it may lack a little of the body and oomph of organically grown nugs.

How Do Aquaponics And Hydroponics Differ From Each Other?

Aquaponics and hydroponics are both methods of growing plants in water, but they use significantly different techniques. 

Aquaponics cannabis growing
Aquaponics system.

In hydroponics, the plants are grown in a nutrient-rich solution and require little or no soil. In aquaponics, the plants are grown in a tank or other container that contains both water and fish. The fish waste is broken down by beneficial bacteria into nitrates, which are used by the crop as the main source of nutrition. Aquaponics is considered a more sustainable method of growing since it uses the waste produced by fish to fertilize the plants.


So, there you have it. Everything you need to know before going and setting up your very first hydroponic weed setup.  Keep in mind that hydroponics is a great way to get the most out of your growing space and can make the experience of cannabis cultivation super rewarding, both in buds and in satisfaction!

No matter if you’re a beginner or a seasoned grower, hydroponics is definitely worth considering, but always do your research before dropping that hard-earned cheddar on a system you don’t fully understand.

And hey, happy growing friends!

Picture of Sam North

Sam North

Sam North is a content writer with a passion for everything cannabis. After working multiple seasons on weed farms absorbing the ins and outs of cannabis cultivation and culture, he decided to transition into a role that would allow him to work from anywhere, anytime. Sam now writes for multiple weed publications. He has extensive experience with a wide range of canna-agriculture styles, from smaller artisanal farms to large-scale commercial operations, and is here to share his knowledge to give you all the best chance of cultivation success. About this Author

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