The best hydroponics system for growing cannabis is usually the one that suits the grower, rather than what the plants prefer. There are many different ways to grow in hydro too, from fully automated systems to systems you have to water by hand every day. A lot of the decision will be based on your budget and your experience with growing cannabis in hydro systems.
In this guide, we are going to cover the main types of hydroponic grow methods. We will discuss the basics of each one and run you through a list of pros and cons so you can make an informed decision on what the best hydroponics system for growing cannabis is.
But before we move on to that, we should briefly explain what hydroponics means and how it works as a grow medium.
What is Hydroponics
Hydroponics is essentially growing plants without the use of soil. This means the plant is grown in a grow medium like coco, rockwool, perlite, or even just straight tap water. There are no nutrients in the hydroponic grow mediums, and very little microbial life. You have to add everything the plants need to the grow medium to make sure they stay well fed.
The most recognisable hydro grow methods would be growing in water. The roots are suspended in the water, and this is where they will get their nutrients. But hydro does not just mean plants grown in water. Mediums like coco, rockwool, and perlite are all seen as “soilless mediums” which are also considered hydroponics.
So the act of growing hydro can span across a few different methods. Some will need more equipment, time, and attention than others. You just have to choose which one you think suits your style best.
Types of Hydroponic Grow Mediums
Before we move on to different ways of growing cannabis in water, I thought it would be a good idea to talk about soilless grow mediums first. These mediums have no nutrients in them at all and are more there to hold the roots in place, and deliver water and nutrients to the plants via those roots.
All of the nutrients provided to plants in soilless mediums are given to them by the grower when the plant is watered. It is just a medium that holds the water and nutrients you provide to it, while at the same time holding the plant’s roots to keep it stable.
There is one type of soilless grow medium that deserves guides of its own. It is very popular and can often be overlooked as a hydroponics grow medium. This medium is called “Coco.”
Is Coco Coir the Best Hydroponics Growing Method?
Coco coir is definitely one of the most popular mediums used for growing cannabis. The ratio at which it holds water and nutrients is very well suited for cannabis plants. As a result, plants in coco are very hard to overwater, and giving the plants exactly what nutrients they need is very easy to do too.
To grow in coco, all you have to do is fill your pots with coco and plant your plants into it. You then water/feed the plants every day with whatever nutrient ratio they need until harvest time. There are no air stones, pumps, or aquarium coolers and heaters needed. It is a very cost-effective way to grow cannabis hydroponically, and perhaps one of the easiest too.
Pros and Cons
- Coco coir has excellent water retention, so it is really hard to over water plants in coco
- It has good aeration, so the roots can get plenty of air when they need it
- Coco coir can be reused for multiple grows, you will just need to “buffer” it to use it again
- Very easy to work with! Though it may seem confusing at first, once you get over the basics, coco is very easy to grow in.
- Coco can leach calcium from your nutrient solution, taking it away from your plants
- Compared to soil, coco coir has fewer beneficial microbes in the medium
- You will need to water coco everyday at least to keep the medium wet and to prevent “EC spikes”
- Coco is made from coconut fiber, and has to be shipped all around the world. This isn’t ideal for eco-friendly growers.
Using Rockwool as a Grow Medium for Cannabis
Rockwool is a soilless grow medium. Many growers will use small rockwool cubes to get their plants started before moving them into full hydro setups like DWC and NFT.
Much like coco, rockwool has no nutrients in it; you have to add them all. Also, the way rockwool retains water is very good for cannabis plants. But do bear in mind they can dry out quickly and should be kept damp at all times.
You don’t just have to use rockwool to get plants started, though. It can be used to grow a plant all the way through its life cycle. You just have to use a rockwool cube that’s big enough for the root zone.
- Has good aeration so the roots can get plenty of oxygen.
- Rockwool is suitable to use with numerous hydroponic systems, such as DWC and NFT.
- It is pH neutral, so you can control and adjust the pH of the nutrient solution easily.
- Rockwool is a sterile medium, which will reduce the risk of pests and diseases.
- Small rockwool cubes are often used for germinating seeds and rooting cuttings.
- Rockwool can be an irritant to the skin and lungs, so be careful when handling it
- It can dry out relatively quickly, so you should water it often.
- Rockwool degrades over time so you will only be able to resume a few times before it needs replacing.
Hydroton, AKA Clay Pellets
Clay pellets can also be used as a grow medium. But for hydroponic systems like this, you should have a steady flow of water flowing through the root zone at all times. Clay pellets are reasonably big compared to particles in other grow mediums. So the roots have plenty of space to grow, and they can get as much air as they need.
Because of the gaps between each pellet, air and water can flow easily through the whole medium and get to the roots where they are needed.
In most cases, however, clay pellets are not used as a grow medium for the whole grow. They are just there to hold the plant in a small pot until the roots grow out of the bottom. The roots will then be suspended in other hydro setups like DWC, NFT, and Ebb and flow.
So, though you can use clay pellets as a grow medium for the whole grow, they tend to be used just as support for smaller plants until the roots can hit the water/nutrient solutions.
- Good aeration and drainage for plant roots.
- Reusable, making it a cost-effective option in the long run.
- They are pH neutral, allowing you to have better control over the nutrient solution’s pH.
- Does not contain nutrients, so you can control nutrient intake.
- Lightweight, making it easy to work with and handle.
- Stable Structure: The pellets maintain their structure well over time, providing stability for plant roots.
- The upfront cost can be relatively high compared to some other grow mediums.
- Clay pellets can produce dust when handled, consider rinsing them before use.
- Small pellets may lead to blocked pipes and pumps if not handled properly.
- Clay pellets do not hold water well, so they need watering often.
Using Perlite as a Grow Medium
Perlite is often mixed with soil or coco to improve drainage. However, it can also be used as a soilless medium for growing cannabis. Perlite is placed into pots, plants are then planted into it, and it is treated like a grow in clay pellets.
Not many growers would choose to exclusively use perlite for growing their cannabis plants unless there is a specific reason. Some stealth grows with small cannabis plants may use perlite because you can water the plant often and not have to worry about over watering them at all. But it isn’t considered ideal as a grow medium for larger plants.
- Perlite is very lightweight, making it easy to handle and transport.
- It has excellent aeration so the roots can get plenty of air.
- Perlite can be reused after proper sterilization, making it a cost-effective option.
- It has excellent drainage so it is difficult to overwater plants growing in perlite
- Handling perlite can produce dust, which you shouldn’t breathe in. So it’s important to use a mask when working with it.
- Perlite tends to float in water. This can easily block pipes and tubes in hydro setups and auto watering systems.
- Can easily grow algae on the perlite if it isn’t kept clean
DWC, Deep Water Culture
DWC stands for Deep Water Culture. It essentially involves growing cannabis in deep water. In most cases, a plant will be grown in a large bucket, and that bucket will be filled with water containing the nutrients the plants need.
An air stone is added to the bucket. This allows lots of oxygen to get directly to the roots and can result in extremely fast growth. There is also RDWC, which stands for Recirculating Deep Water Culture.
RDWC is when the water in the buckets recirculates via a main reservoir. The EC and the pH of the reservoir are kept in check, and the water/nutrient solution flows into all of the buckets. This keeps the reservoir fresh and ensures that exactly the same feed is delivered to all of your plants in the system.
NFT, Nutrient Film Technique
In NFT grows, plants are suspended in the air inside a big tub or tray that collects water. This water is pumped onto the top of this tub so it pours into holes that hold the plants. The water then runs over the roots of the plants and back into the reservoir it came from.
A constant flow of water and nutrients will run over the plants, providing them with all the nutrients and water they need whenever they need it. In the reservoir, there is also an air stone that adds lots of oxygen to the water. This gives the roots an extra oxygen boost as they are being fed.
You need a specific setup to grow NFT, and it will not be cheap to get everything you need. But this method is very easy, takes minimal work, and will produce huge plants!
Ebb and Flow, AKA Flood and Drain
Ebb and flow is somewhat like NFT and RDWC mixed together. But instead of a stream of water constantly flowing over the roots, the roots get flooded, and then the water drains away. Hence the name, flood and drain. For lack of a better way to describe it, think of your toilet.
When you flush your toilet, the water from the tank floods into the toilet bowl and is poured away. The tank then fills back up ready to be flushed again. The same thing is happening with flood and drain. But the water is flushed away, then put back into the reservoir to be given to the plants again.
This happens numerous times a day and is just a constant cycle of flooding the roots to give the water and nutrients, then draining them to give them oxygen. Like most types of hydroponic growing methods, this one will produce huge plants, but running this setup takes a lot of maintenance.
Aeroponics is when the roots of the plants are sprayed with a nutrient solution using a mister. The nutrient solution is stored in a reservoir. It is then pumped into a mister spray where it coats the roots of the plants. The leftover moisture is then collected, added back to the reservoir, and the process begins again.
It is a very efficient way of delivering water, nutrients, and air to the roots of the plants, and they grow very quickly because of it.
The biggest problem with aeroponics is the potential failure of pumps and mister sprays. If they break, and the roots of the plants are not being kept damp, they will dry out and die. Not many growers use aeroponics as a home grow, as there are many types of hydroponic growing systems that are much easier to set up and maintain. But aeroponics does produce crazy yields!
Pros and Cons of Growing Cannabis in Full Hydro Systems
- Faster Growth: Hydroponic systems allow the roots of plants easy access to nutrients, water and oxygen. As a result, they grow quickly
- Higher Yields: Because the plants have as much food and water they need, they grow quicker, and can produce more buds in a short space of time.
- Less Waste: Recirculating hydroponic systems use less water than soil-based growing, as water is recirculated and used many times. There is also no soil to get rid of after after grow is done!
- Nutrient Control: It is easy to monitor and adjust the nutrient solution when growing in hydro. So you can add or take away nutrients as and when the plant needs it.
- Reduced Pest Issues: Lots of types of bugs that like cannabis will lay eggs in the soil of the plants. Because there is no soil, there is less chance of bugs laying eggs.
- pH Control: It is easy to monitor and adjust pH and EC in hydroponic grow mediums. This will reduce nutrient imbalances and keep your plants happy.
- Initial Cost: Setting up a hydroponic system will require more equipment than soil grows, as a result, it will cost more to set up.
- Complexity: Hydroponic systems are more complex than cannabis grows in soil. Setting up the grow is more complex, and growing the plants is too.
- Equipment: Hydroponic systems need pumps, timers, and other devices to run the grow. This increases the cost of setup
- Power Requirements: All the extra equipment will need power to run it, increasing the cost of energy bills.
- Maintenance: Regular monitoring and maintenance is important to prevent equipment failing. You also need to monitor the EC and pH of the medium often to ensure its at the correct level.
- Risk of Equipment Breaking: If pumps, timers, or other equipment break, it can lead to plants not getting the water, nutrients and oxygen they need. As a result they can die!
- Learning Curve: Learning how to grow cannabis in hydro will take some learning, and patience before you are fully comfortable with the system.
Choosing the Right Hydroponics System for Growing Cannabis
Taking all these factors into consideration should give you an idea of what is the best hydroponics system for growing cannabis. For beginners, I highly recommend starting with something like coco. It’s an excellent medium, easy to troubleshoot if issues arise, and relatively inexpensive to begin with because it doesn’t require extra equipment like pumps, aquarium coolers, or heaters.
However, if you’re more interest in the full hydro style of growing cannabis, Deep Water Culture (DWC) is maybe the best hydroponics system for growing cannabis. It can produce large cannabis plants in a relatively short time, potentially shaving 2-3 weeks off the entire grow cycle compared to soil. But this is just my opinion, you may like to use a different method.
Once you’ve decided what type of hydroponics grow system you’re going to use, head over to one of the many guides on our cannabis forum. These guides will take you through each medium in finer detail. We will cover setup, equipment, and how to feed and maintain a happy cannabis plant in your chosen medium.
Conclusion on the Best Hydroponics System for Growing Cannabis
Share your thoughts on the best hydroponic medium for growing cannabis! Whether you’re an experienced hydroponics grower offering recommendations or a new grower looking for advice, our cannabis growers forum is open for you to join. Join the community to share your knowledge or learn from others. No matter your level of experience, you can find help, answers, and a sense of community in our cannabis growers forum. Come and join us!
I hope this guide has help you decide what the best hydroponics system for growing cannabis is. Let us know if this article has helped you to make a decision. We would love to hear from you. Thanks for reading! See you in the forum!