Your Ultimate Guide to the Kratky Method for Growing Cannabis
Say hello to the Kratky Method — a straightforward hydroponic technique that’s perfect for anyone looking to grow cannabis with less hassle. If you’ve ever felt overwhelmed by other hydroponic systems, this method could be your answer to simpler, more efficient cannabis cultivation.
But what is Kratky and how do you get started? In this article, learn everything you need to know about the Kratky method, along with some extra tips!
Image Credit - Dnamra
The Kratky Method is a low-maintenance method to grow cannabis that might just become your new favorite hydroponic technique. This method was named after BA Kratky from the University of Huawei and is a simplified version of deep water culture (DWC).
However, unlike DWC, you won’t need any pumps to make it work! So, that translates to no noisy or power-hungry pumps for growing cannabis hydroponically. You also don’t have to constantly mess with the nutrient solution. The Kratky method is all about minimal fuss and low cost. There’s no need for fancy equipment or ongoing expenses.
Here’s a quick rundown on how it works:
It might sound like it’s too good to be true, but it’s a reality for many growers. While it’s true that hydroponics can seem intimidating at first, especially if you’re used to soil which can be more forgiving, this method simplifies things significantly.
Yes, you’ll still need to monitor pH and water levels, but it’s not as tricky as other hydroponic setups. So, if you’re planning to grow a few small cannabis plants, this method is a good choice. It’s self-sustaining for weeks as long as you keep an eye on it.
Let’s dive into how this whole Kratky method works. As mentioned, it’s pretty similar to DWC but without the extra gadgets or gizmos like pumps or wicks.
So, just like any other hydroponic system, your plant needs four key things to thrive:
As your cannabis plant grows, it will drink up the water from the reservoir, causing the water level to drop. You’ll need to keep an eye on this and top up the reservoir as needed if the plant isn’t ready to harvest yet.
Here’s what makes this method so effective — simplicity! The system effortlessly provides water and oxygen to your plant. So, your main tasks are to ensure your plant gets enough light and nutrients. Compared to other hydro setups, this one requires minimal fuss and is incredibly efficient.
In a nutshell, as your plants drink up the water, they absorb nutrients and create an air gap for oxygen. This is perfect for cannabis, which grows quickly and thrives in this setup. In fact, by the time your plant has used up the water, it’s often ready for harvest!
Kratky is used to grow a lot of plants, including cannabis. Here are a few benefits to help you figure out if this system suits you.
This is one of the major reasons why the Kratky method for hydroponics is perfect for growers who don't want to deal with a lot of stress when growing cannabis.
As a passive system, there are no pumps, which means there's no need for electricity and you can leave the plants without too much maintenance.
The Kratky method differs from other forms of hydroponic systems like DWC or other complicated types like aeroponics where you have to monitor the plants quite a bit. You also won't need any equipment to help the water and nutrients circulate to the plants, which is the essence of most hydroponic systems.
Once your Kratky system is running, you don’t need to monitor it constantly. Although you’ll have to check the pH and nutrient levels that will have to be modified at intervals, it makes an ideal candidate for growers who are short on time and just want to grow good cannabis with minimal effort.
However, before you get too excited, note that you'll have to monitor the water levels at all times. We will discuss that in the next section.
Compared to other hydroponic systems, it involves very little upfront investment. Other than the containers, nutrient solution, and grow lights, you don't have to spend much on anything. Thus, if you don't have a large budget to grow cannabis, pay attention to how Kratky works and you might just grow a few plants with it. In addition, beginners can experiment with this system until they get the hang of how cannabis grows.
It is an energy-efficient way to grow cannabis as it doesn't depend on electricity to run pumps or aerators. you'll not only save some money but also produce the buds in an eco-friendly manner, which is great for the environment.
The Kratky method is well known for its simplicity. All you need are a few net pots containing a good growing medium. Next, you need to fill the container with water and nutrients and introduce the roots to the water. The roots will be both above and below the surface as the water level drops, so they can take in oxygen and nutrients at the same time. It makes it one of the best options for beginners due to its simplicity.
Hydroponic systems typically produce a little noise due to the pumps. But, since Kratky doesn’t depend on pumps, it operates silently, which is simply perfect for those who love a discreet setup. As there isn’t a lot of mechanical equipment, you’ll not even notice that the plants are growing inside a tent.
Kratky is efficient even in conserving water. Once you add the nutrient solution to the container, it continues to drop slowly as the plants use it. You can then refill it when the levels are low. As you can see, their water consumption is very controlled, so there’s no problem with overwatering or underwatering as the plants absorb water as and when they see fit.
The reason why users love Kratky to grow cannabis and even various types of vegetables is that it provides many of the same benefits of common hydro setups sans the expense and headache. If you’re a beginner who wants to experiment with cannabis without shelling out too much money, the Kratky system is really the way to go.
Sure, the Kratky method sounds awesome, but before we move ahead, you should acknowledge its drawbacks. It has a few, such as the following.
This system is sensitive to changes in pH levels and temperature. If you don’t keep these in check, your plant’s growth can take a hit. Because the Kratky method does not involve active water circulation, it can be difficult to maintain stable water temperatures. If the water gets too warm, it can lead to bacterial growth causing root diseases and other problems. Conversely, the plants struggle to intake nutrients if the water gets too cold. Other hydroponic systems maintain stable temperatures as the water keeps moving, but since Kratky is a passive system with no water movement, you'll need to ensure that the temperature of the water doesn't fluctuate too much.
The Kratky method is ideal for small cannabis grows, but scaling up can be a real hassle, involving lots of manual labor to clean and manage multiple systems. You may find it hard to keep up with the water levels and nutrient imbalances when the plants need more water. It’s not exactly the best choice for a large-scale operation.
Without air stones to keep the nutrient solution moving, the water can become stagnant. This stagnant, nutrient-rich environment can attract pests like gnats and mosquitoes. Be ready to tackle these pests head-on to keep your growth healthy.
The Kratky works fine for cannabis plants during the vegetative stage when it needs less water and nutrients. However, the plants may need more water during the flowering stage, and the same goes for nutrients too.
So, when the plant transitions to the flowering stage, it can get difficult to keep up with the plants’ demands with a Kratky setup. Also, the plants need more oxygen during the flowering stage and since Kratky falls short in that department, you may have to switch to another type of hydroponic setup midway.
Oxygen is made available to the roots in a regular hydroponic setup through water circulation and aeration. In Kratky, the roots rely on the space between the water and the roots, which can create problems if the water is not managed correctly. If you don't notice the water levels dropping too quickly or if the container you're using is very shallow, the roots can get suffocated as there's no aerator or pump.
In addition, if you fail to refill the nutrient and water solution once it depletes, the plant can face drought and start wilting. Next, you might notice stunted growth and even death in extreme cases. This part is especially important if you're growing strains that drink a lot of water during their life cycle. Some plants may not need a lot of water, but other strains can be very thirsty, so you need to be very careful about the water levels to ensure that the plant doesn't suffer.
Since the cannabis plant consumes water from the nutrient solution, the concentration of nutrients remaining in the water can vary over time. For instance, if the plant absorbs water faster than it can intake nutrients, the concentration of nutrients can exceed the recommended levels.
Conversely, if the plant consumes nutrients faster than it can absorb water, it can experience nutrient deficiencies. Thus, you'll have to check the nutrient levels periodically, which can be slightly challenging as the water is stagnant and isn't dynamic, unlike other hydroponic setups.
When nutrient-rich water is left open to light, algae will begin to grow rapidly on its surface or inside the container. The problem with algae — apart from looking gross on the roots — is that it competes with the plants for nutrients. Not only will your plants struggle to my get the nutrients meant for them, but you'll also lose money since nutrients can be quite expensive. As this system doesn't use any filtration systems, it can be difficult to control the growth of algae.
The Kratky method is more suitable for quick growth cycles where you don't have to adjust the nutrients and water constantly. However, if you're growing a strain that takes a long time to grow and flower, this system can get less effective.
Kratky is a simple hydroponic method where you don't have to use lots of equipment, which is an advantage. However, this can be a disadvantage too as you don't get to control a few aspects of how your plants grow with this system. For example, you can't control the oxygenation and can only hope it all works out well. This can be a turn-off for growers who expect hydroponic systems to offer a lot of control.
While the Kratky method offers some great benefits, these are the trade-offs you should be aware of. If you’re okay with managing these issues, this system could still be a great choice for your cannabis cultivation.
But, although the Kratky method is a great tool for cannabis cultivation, it's not flawless. Grasping the possible cons of this passive hydroponic method can help you decide whether you want to go ahead with it or not.
It’s pretty simple to set up a nice Kratky system at home. As mentioned earlier, you don’t need a lot of equipment. Here’s how you do it.
Now we can begin, and the first step is to gather the supplies. Here’s a list of everything you need to get started.
The size of your container depends on your plant size. You could start with a small mason jar for a single plant, but for bigger grows, a 5-gallon bucket or even a larger tank might be necessary.
A good lid is crucial. It prevents the nutrient solution from evaporating and keeps your plant perched above the water. Plastic or Styrofoam lids work well for this.
These are your plant’s best friend. Net pots have holes in the bottom to let nutrients reach the roots and allow excess solution to drain. They’re a must-have for a successful harvest.
Your plants need something to root into, and that’s where these come in. Here, you can use coco coir (sustainable and biodegradable), rockwool (porous), clay pellets (lightweight pebbles), or perlite (excellent aeration).
For the Kratky method, you’ll need a mix of Masterblend fertilizer, calcium nitrate, and magnesium sulfate, usually in a 4-18-38 ratio. Adjust the amount based on your container size and water level. If you don’t have this particular brand, you’re free to try any aother nutrient of your choice, However, make sure you use it according to the stage of growth.
To fine-tune your setup, you might also want a pH control kit and a ppm meter. If you're looking for an all-in-one solution, you can even find Kratky starter kits on platforms like Etsy.
Ready to grow cannabis with the Kratky method? Follow these five steps.
Start by prepping the lid for your reservoir. Use a drill or another cutting tool to create a hole big enough for your net pot. This lid will hold your plant above the nutrient solution, so make sure the hole is the right size.
Next, fill your reservoir with water. You can use either tap water or distilled water but steer clear of dirty or contaminated sources. Since the water will sit stagnant, you don’t want to invite any pests into your setup!
Add your nutrients to the water in the reservoir. You can either mix them directly in the reservoir or blend them in a separate container before pouring them in. Ensure that the nutrients are well-mixed to give your plants a balanced feeding.
Your setup is almost complete! Use a pH pen or meter to check the pH of the nutrient solution. For optimal cannabis growth, aim for a pH range between 5.5 and 6.5. And if the pH isn’t within the ideal range, adjust it accordingly before you move on. Proper pH levels are crucial for nutrient uptake and plant health.
Fill your net pot with your chosen growing medium, then insert your cannabis seedling. Place the net pot into the hole you drilled in the lid. Make sure some of the roots are exposed to air while the lower parts are submerged in the nutrient solution.
And there you have it! With these steps, you’ll have your Kratky system set up and ready to grow. Just keep an eye on your plants, check the water levels, and enjoy watching your cannabis thrive!
As you already know, there are a lot of benefits to growing with the Kratky system. But, there are a few limitations and you can overcome them only if you pay attention to some key factors that can make your project successful. Here are some tips to help you nail this technique to the T.
Everything depends on the water in this system as you don't have many other components. You must maintain high-quality water, which should be easy since you won't be spending too much on other stuff with this method. As the roots of the plant are immersed in water, you must ensure that it's clean and filtered with no contaminants that can slow down or kill your plants.
If you're using tap water, let it sit in sunlight for at least 24 hours so that the chlorine evaporates.
And, as mentioned earlier, you must keep an eye on the water levels regularly. If you fill in too much water, the roots will sit in stagnant water for long periods and cause issues. On the other hand, if you don't fill in adequate water, it can deplete quickly and dry out the roots.
For this reason, get a big container that has the capacity to hold enough water to satisfy the plants. It should be wide enough to provide a gap between the roots and water.
If you're using multiple net pots, ensure they’re spaced out properly. Overcrowding can lead to competition for nutrients and light, reducing your yield.
Every hydroponic system needs adequate light for the plants to grow efficiently, and Kratky is no different. In addition, the light must be intense and you should provide enough light, depending on the plant’s stage of growth. Whether you're growing indoors or outdoors, the plants will need at least 18 hours of light and 6 hours of darkness in the vegetative stage and 12 hours of light and 12 hours of darkness during the flowering stage.
Most hydroponic systems will use air pumps to actively oxygenate the water, whereas the Kratky method relies on an air gap between the roots and the water. The problem is that if the gap is too narrow or if the water is too stagnant, roots often fail to receive enough oxygen and growth may be limited.
To prevent this, make sure there's a good gap of air between the water and the roots and the plants will get some oxygen once they start consuming the water. If this becomes an issue, simply add an air pump to increase the aeration.
Even though Kratky is low-maintenance, periodic cleaning of your reservoir and equipment helps prevent algae growth and nutrient buildup.
The nutrient solution is the only way for your plants to absorb nutrients, so you must use high-quality nutes in the right ratio. Rather than trying to mix your own nutrients from scratch, it's best to purchase commercial nutrients that contain both macro and micronutrients to support the plants.
Check the level of Electrical Conductivity (EC) frequently as there are high chances of nutrient imbalances that can occur when using Kratky. For this reason, the plants can suffer from nutrient burn too, so start with a less concentrated solution and increase the potency only if necessary.
The pH plays a major role as well since most imbalances are a result of pH fluctuations. And, just like nutrient imbalances, the Kratky system is a little more susceptible to pH fluctuations than other types of hydroponic systems.
Therefore, you must make sure that the pH is always between 5.5 to 6.5 so the plants can absorb all the necessary nutrients. If the pH is too high or two low, then the plants cannot absorb the nutrients even if you feed them, which is why nutrient deficiencies and toxicity occurs.
Like all hydroponic methods, the Kratky system will also be efficient if the environmental conditions are controlled properly. This means that the temperature should be steady. Typically, cannabis plants like a temperature between 70°F — 85°F (21°C — 29°C) and you can vary them slightly depending on their stage of growth. In addition, you must manage the humidity to keep mold and mildew at bay that will grow quickly in the damp surroundings of a hydroponic configuration.
We have already mentioned the importance of using the right container in the Kratky system as it can seriously influence how your plants grow. As discussed already, get large containers or the roots won't be able to grow downward along with the water level. Also, make sure they are opaque to keep algae out. It won't hurt to use food-safe containers to prevent any sort of chemicals from leeching into the water.
Some cannabis strains perform well with the Kratky method as they may be better suited than others for passive hydroponic setups due to their size, nutrient needs, and root structure. However, you may quickly notice that some strains will struggle a lot with this setup. Therefore, selecting the right strain becomes very important if your mind is set on using the Kratky system.
First off, purchase short, bushy strains like Indicas or at least Indica-dominant hybrids as this system will not support very large plants. You can even go for autoflowers as they are smaller than the larger photoperiod varieties. Still, modern autos can grow very large, so make sure you get a smaller one.
Also, it’s important that you choose strains that have a short flowering period. Do not opt for photoperiod varieties that take months to flower or you’ll have a hell of a time keeping up with the water levels and nutrient imbalances that can occur over time. Again, autoflowers are perfect as they are quick to flower too.
As mentioned earlier, you should still keep an eye out for any pests or diseases that could damage your plants. Poor water quality or environmental conditions can lead to algae growth, mold, and root rot in a passive hydroponic system.
Check the plants for spider mites, aphids, and other most common pests. Also, make sure that you have proper airflow and ventilation to avoid pests. To avoid mold growth, make sure there’s proper airflow and ventilation.
Algal growth is a problem in most hydroponic systems, but Kratky is particularly vulnerable to it since the water reservoir is intermittently exposed to light. Algae grow quickly in any environment that offers a lot of moisture, and since hydroponics is all about water, you should be careful no matter what setup you choose.
Unlike pests, algae don't pose any direct harm to your cannabis plants, but it can be problematic in other ways, resulting in some major hindrances to plant health and growth.
Problems associated with Algae Growth:
Nutrient Competition: Algae will eat up the nutrients in your water, meaning your plants don't have enough nutrients. This can lead to imbalances and you'll be wondering what went wrong even after providing all the nutrients.
Oxygen Depletion: Algae growth and decomposition use up a lot of oxygen in the water. This keeps the roots from getting all of the oxygen it needs, and can even kill the plant because the roots suffocate.
Clog: Algae can create a slimy layer on the water or block up your roots, reducing their ability to take in water and nutrients as easily. It can also clog the pipes and equipment, preventing them from working properly.
To prevent algae, the easiest and cheapest method is to use opaque containers that block light from getting into the water.
In addition, cover any surface of the container that's exposed to light. Clean the water reservoir routinely and look for any development of algae. If you spot green patches, which is algae, empty the container and clean it well before refilling with fresh, nutrient-rich water.
In addition, algae growth is correlated with warm water. Thus, monitor the temperature of your water and don't let it get too warm.
Finally, introducing beneficial microbes or enzymes to the water will help as they outcompete algae and break down organic material, preventing the algae from growing further and also supporting healthy root development.
With the Kratky Method, growing cannabis can be really easy. This technique’s simplicity and efficiency make it an appealing choice whether you are a beginner or seasoned.
By following the steps outlined, you'll have a streamlined setup that provides your plants with everything they need to thrive — without the constant upkeep of more complex systems.
Just remember to keep an eye on water levels, pH, and light to ensure a successful harvest. Start growing cannabis with the Kratky method today!
