Aquaponics combines two systems to grow plants and fish for consumption. Learn all about how to grow cannabis with aquaponics. You grow plants in soil, right? Not with hydroponics! Read here whether growing cannabis on water can also be a solution for you. Whether you call it weed, cannabis, pot, marijuana, or something else, the plant known as Cannabis sativa is actually easy to grow at home when you know what you need to do. Growing hydroponically will provide you with higher yields and a…
An introduction to growing cannabis with aquaponics
Aquaponics is a growing technique that combines two efficient systems: Aquaculture, a process of farming fish such as tilapia, koi, or bluegills, and hydroponics, a method of growing plants without soil. When the two are combined, you can create a nearly closed loop system that produces both plants and fish for consumption.
How do aquaponic systems work?
Aquaponic setups are very similar to hydroponic setups, but the source of nutrients for plants is different—nutrients come from the waste of the fish. The plant roots absorb the nutrients and then purify the water before nutrients are returned to the aquarium. Fish food is the only input you’ll need, and this can be grown or purchased.
The primary nutrient produced from fish waste is nitrogen with trace amounts of other minerals. Because of this, basic aquaponic systems are great for vegetative growth, but you’ll need to add additional nutrients like phosphorus and potassium for flowering. This can also be remedied with a double-root zone.
A double-root zone allows you to divide roots into two sections: The bottom half of the pot gets submerged in water, while the upper half of the pot can be filled with soil. This allows additional nutrients to be applied to the roots without contaminating the water.
The two sections can be separated by burlap, which allows roots to travel through while preventing soil from reaching the water. When watering with additional nutrients, avoid oversaturating the soil to keep the water below in the aquaponics system clean.
Aquaponics vs. hydroponics for weed
Aquaponics utilizes a hydroponic setup for growing weed, with the addition of fish in the water chamber. This allows you to skip putting liquid nutrients in plants and instead rely on the waste of fish, a more natural source of nutrients.
The other main difference is the cultivation of fish in addition to cannabis.
Best fish for growing cannabis with aquaponics
Some considerations before choosing fish for your aquaponic setup:
- Water temperature
- Tank size
- Maintenance difficulty
Some fish need warmer water than others, so you may need to invest in a water heater or be sure your setup is in a warm place. Some fish are also bigger than others or more difficult to maintain, requiring more labor or money.
Here are types of fish most commonly found in aquaponic setups because of their low maintenance and versatility:
Advantages of growing weed with aquaponics
- Sustainability: Aquaponic systems use the waste of one organism to feed another. Fish food manufactured specifically for aquaponic systems ensures your plants will be free of toxins, and the plants will help fish grow strong and healthy.
- Growth rate: Aquaponics is a great way to grow cannabis plants quickly. By allowing the roots to take in high levels of oxygen they are able to absorb more nutrients and will thrive.
- Water use: Aquaponics systems use considerably less water than traditional systems because they recirculate water.
Disadvantages of growing weed with aquaponics
- Initial costs: Setting up an aquaponic system is more costly than a soil or even hydroponic setup.
- Maintenance: Fish need water in a specific temperature range, so you’ll need more equipment and resources to warm or cool water, and it will require more work to maintain.
- Algae: As with a hydroponic system, there’s a lot of moisture, requiring you to be on high-alert for algae growth that can harm your plants. Aquaponic systems require cleaning and sterilization to protect plants from algae.
Common challenges when growing weed with aquaponics
Growing weed in a hydroponic setup can be challenging enough, and growing in an aquaponic setup is even more difficult. Growing with aquaponics is not recommended for first-time growers.
Aquaponics can get complicated because you have two focuses: plants and fish, instead of just worrying about your weed plants.
As with growing in hydroponics, using water as your grow medium can be challenging and generally involves more equipment, time, and money.
A tricky thing with aquaponics is being able to balance the fertilizer from the fish that goes into your plants. If growing with aquaponics, be sure to have a firm grasp of nutrients and pH levels, and how to balance them.
How to set up an aquaponic weed garden
The easiest way to start an aquaponic setup is to repurpose an old fish tank and pump. Be sure to dechlorinate the water and allow it to cycle for 4-6 weeks before adding any fish.
Then you’ll need to create a media bed for the plants. Some growers use one big flood tray for a number of plants, and some use individual pots, as in the graphic above.
Then add the fish, and then the plants, and you’re ready to go! Just feed the fish to begin the cycle, and they will create fertilizer for the plants in no time.
Hydroponics: Growing Cannabis Without Soil
If you’re thinking about growing cannabis plants, chances are you’ll think about pots filled with soil. However, in hydroponics, weed is grown in water instead of soil. This technique is also known as hydroculture or RDWC (Recirculating Deep Water Culture), but hydroponics is the most usual term. This method is not as complicated as many people think. Actually, growing gets easier with this technique, as plants will grow faster because they can absorb more nutrients. Hydroponics is suited for just about any plant, but it works especially well with vegetables and cannabis. This blog tells you just what hydroponics can do for you as a cannabis grower.
How Does Hydroponics Work For Cannabis Growers?
To be fair, hydroponics sounds like a pretty impressive technique. The word itself comes from the Greek concepts of ‘hydros’ and ‘ponos’ (‘water-work’; the ancient Greeks worshiped Hydros as an old god of water, and Ponos as the god of hard work). Ironically though, hydroponics done right isn’t hard work at all. Of course, it’s a matter of preference in the end, but most growers agree that hydro grows are easy once you get you get the hang of it.
Hydroponics is on the rise; mostly because it gives growers greater control over how their plants develop. Instead of growing your weed plants in soil, you grow them directly in water containing all necessary nutrients. That comes with some distinct advantages, making this technique an interesting option for advanced and amateur growers alike.
Liquid Lunch: Nutrients Straight From The Water
In hydroponics, plant roots are suspended straight in the water rather than in soil. That makes water the substrate or grow medium. Substrate is just a fancy term for ‘bottom layer’ (‘sub’ + ‘stratum’). Such layers can be anything from sand or rockwool to coco fibre, gravel, or clay pellets. In cannabis hydroponics, water is the grow medium; even if there’s a layer of clay pellets in the top section of a (floating) pot for stability. Nutrients are dissolved into the water and delivered straight to the roots. Any water that is not absorbed is recycled by the system for future use. Roots of plants grown in hydroponics tend to be longer and paler than their soil-grown counterparts, with fewer side branches. This is caused by the low oxygen content of water compared to soil.
Basically, any plant can be grown using hydroponics. Cannabis thrives on it, but these days, you’ll find entire farms growing lettuce and leeks on water alone. Fun fact: the increasing popularity of growing cannabis at home has been one of the driving forces behind the development of new hydroponics systems used in regular agriculture!
Cannabis Hydroponics Basics
The diagram below shows the basic components of a simple hydroponics setup for cannabis growers.
1: Substrate; in this case, water containing nutrients. Some systems have plants suspended directly in water, while other favour pots with a top layer of clay pellets for extra support;
2: Cover preventing evaporation and contamination of the substrate. This is usually a floating lid with holes providing a snug fit for suspended plants;
3: Aeration or oxygenation; usually in the from of an exhaust unit blowing air bubbles into the water;
4: Air pump. Many hydro setups feature a separate water pump with a filter to keep the water clean while circulating.
Different Cannabis Hydroponics Systems
The one thing all hydroponics systems have in common is the lack of soil needed to grow your cannabis plants. Hydroponics gets your cannabis plants everything they need, except light: nutrients, oxygen, and water. This can be done in several ways. Below, you’ll find a summary of the most common hydroponics systems.
(R)DWC: (Recirculating) Deep Water Culture.
(R)DWC: (Recirculating) Deep Water Culture
RDWC is the easiest system to manage, making it a great option for beginners. You put your germinated plants into individual containers, which you then place into a water container. All you add is some hydro pellets to give the roots some added grip. An air pump ensures a constant air supply into the water. Nutrients are added to the water, which the plants can then absorb through their roots. That means roots are constantly exposed to water throughout the growth cycle. The R in RDWC stands for Recirculating, because the water is constantly pumped around the system in a closed loop.
RDWC System without plants.
This is a slightly more complex system to use. NFT stands for Nutrient Film Technique. Here, plants grow with their roots in a wide tube, usually made of PVC. The oxygen-rich water carrying nutrients is pumped from the reservoir to the tubes and back. Tubes should be installed at an angle to ensure ample water flow back into the reservoir. The ‘Film’ in NFT represents the ideal situation in which just a thin filmy layer of water and nutrients flows over and along the roots.
This system is great at providing nutrients to your plants. If set up efficiently, it also saves water and power. One potential problem is clogged tubing due to roots blocking the flow. That gives bacteria a chance to grow, which of course will negatively impact your plants. Stay sharp while trying NFT!
Ebb And Flow System
In an ebb and flow setup, the roots are not constantly submerged. A pump regularly fills the container with oxygenated and nutrient-rich water. When the container is full, the pump stops working, allowing the water to flow back into the reservoir. It’s a bit like running your own little mangrove at home. You set the ebb and flow intervals according to what your plants need.
How about running your personal mangrove at home?
Drip irrigation is a popular technique among professional growers all across the agri- and horticulture sectors, but amateur homegrowers will find it very convenient, too. You feed and water your plants using a drip system. Every individual plant gets its own drip nozzle. That allows for very accurate distribution of nutrients, ensuring that every plant gets an equal share. Any liquid not absorbed by the plants flows back into the reservoir for future use.
The Benefits Of Cannabis Hydroponics
Compared to growing in soil, hydroponics can have many benefits.
- You can target your nutrition more accurately, because you don’t depend on what happens to be present in the soil. That allows you to set the perfect nutrient mix without losing valuable ingredients along the way;
- Save yourself work: no need to remove weeds, while the system makes sure your plants are fed and watered. Just keep an eye on the water level in your reservoir. Two refill a week will usually do the job. As you can see, hydroponics is perfect for lazy relaxed growers;
- Your plants will absorb the exact amounts of water and nutrients they need; no more and no less. The system simply recycles any excess water, making it a very efficient system too. Obviously, as a plant enthusiast, you care about the environment: life’s good when you can save the world by growing sustainable weed;
- Pest control: hydroponics environments are cleaner than regular soil. That limits the options for pests and bugs – one thing less to worry about;
- Better yields: plants grow better in hydroponics. For cannabis, that means better yields than for weed grown in soil, all other factors being equal;
- Rapid growth: using a hydroponics setup could reduce the growth phase of your plants by three weeks. Roughly speaking, that could mean two extra harvests every year;
- Not dependent on the weather: hot, dry summer? Freezing cold winter? It’s all the same for hydroponics, because all the plants get exactly what they need, no matter the weather. You don’t even have to keep track of the seasons – if you’re growing indoors, that is.
Drawbacks Of Hydroponics
Using hydroponics for cannabis does come with a few minor drawbacks, though. Firstly, you’ll need to spend more on equipment before you can get your system up and running. Then again, working with the right system eventually pays off in terms of saving on water and electricity.
The second and most important drawback is the tight margin for error that hydro grows offer. Soil has considerable buffer capacity: any surplus of nutrients or lack of oxygen can be compensated in part by the soil and the micro-organisms it contains. Hydroponics barely has any buffer capacity in this sense. Overdosing on nutrients or – worse – power outages will almost certainly damage your plants. That means hydroponics calls for some more vigilance from you as a grower. As long as you know what you’re getting into, though, that should not be a problem.
Outdoor Cannabis Grows Using Hydroponics
Most growers using hydroponics for their cannabis choose to do so indoors. That makes sense from the perspective of optimal control over equipment, lighting, and a bunch of other factors. Such control is slightly trickier to achieve with outdoor grows, but theoretically, hydroponics works perfectly well out in the sunshine. In fact, there are serious plans for using hydroponics as a technique for tackling global hunger issues. Of course, outdoor hydroponics calls for some extra attention to typical open-air factors like the weather, disease, and fungi, but it is certainly an option. A little greenhouse can be a big help, but you don’t strictly need one. What’s more, technology keeps improving all the time, so who knows? You could be running your own water theme park in your back garden come next grow season. At any rate, though, it’s good to know we’ll solve the world’s food problems by the efforts of weed growers such as yourself!
Getting To Grips With Hydroponics
As you’ve seen, cannabis hydroponics opens the door to carefree growing and enjoying better harvests from your weed plants. So, do you feel like starting up your own hydro grow? Give yourself the best possible start with our world-famous cannabis seeds!
How to Grow Marijuana Hydroponically
This article was co-authored by Lauren Kurtz. Lauren Kurtz is a Naturalist and Horticultural Specialist. Lauren has worked for Aurora, Colorado managing the Water-Wise Garden at Aurora Municipal Center for the Water Conservation Department. She earned a BA in Environmental and Sustainability Studies from Western Michigan University in 2014.
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Whether you call it weed, cannabis, pot, marijuana, or something else, the plant known as Cannabis sativa is actually easy to grow at home when you know what you need to do. Growing hydroponically will provide you with higher yields and a shorter grow time compared to growing in soil, but it can often be difficult for the beginning grower to get started with hydroponics. However, most people think of plants growing in water when they think “hydroponics” but actually your plants will get many of the benefits of hydroponics as long as they’re getting their nutrients directly in their water supply. However because of superior air to water ratio in hydroponics, it remains the industry standard. This tutorial will show you step-by-step how to grow your marijuana in 3-4 months using the (arguably) easiest hydroponic method: hand-watering in a soil-less medium.