The Kratky Method – Complete Guide

The Kratky Method is a simple and effective way to grow plants without the need for pumps, aeration, or even electricity. 

This method was developed by Dr. Bernard Kratky, a researcher from the University of Hawaii. 

The Kratky Method is a great way to grow plants for anyone, whether you’re a beginner or a seasoned pro. 

In this guide, we will cover everything you need to know about the Kratky Method, from how it works to what you need to get started.

What Is the Kratky Method for Hydroponics?

The Kratky Method is a type of hydroponics that doesn’t require any electricity or moving parts. You simply set up your system and let the plants do their thing.

The method was developed by Dr. Bernard Kratky, a professor at the University of Hawaii. He was looking for a way to grow plants without using soil, and he came up with this simple yet effective system.

Kratky Method for Hydroponics

Here’s how it works:

You start with a container of water and add some nutrients. Then you place your plant in the water and wait for it to start growing.

As the plant grows, it will develop roots that reach down into the water. The roots will take up nutrients from the water, and the plant will start to grow taller.

Eventually, the roots will reach the bottom of the container and start to circle around. At this point, you can add more water to the container if necessary.

The great thing about this method is that it’s very low-maintenance. You don’t need to worry about constantly checking on your plants or making sure they have enough light or nutrients. Just set it up and let nature take its course!

What Do You Need?

To get started with the Kratky Method, you will need:

  • Clear plastic container or jar
  • A piece of cloth or coffee filter
  • A rubber band
  • Scissors
  • Tape
  • Your chosen plant material

First, cut a hole in the center of your cloth or coffee filter. Next, stretch the cloth or coffee filter over the top of the container and secure it with the rubber band. Make sure the hole you cut is in the center so that your plant material can later be suspended in the middle.

Now it’s time to fill your container with water. The level of water should reach just below where you will be suspending your plant material. Once your container is filled, place your plant material in the hole of the cloth or coffee filter and secure it with tape.

That’s it! Your Kratky Method setup is now complete.

Reservoir or a container

Reservoir or a container is one of the most important aspects of the Kratky method. Without a proper reservoir, your plants will not be able to get the nutrients they need and will eventually die. 

There are many different types of reservoirs that you can use, but there are a few things that you need to keep in mind when choosing one.

First, you need to make sure that the reservoir is big enough for your plants. If it is too small, your plants will not have enough room to grow and may die. Second, you need to make sure that the reservoir has a lid. 

This will prevent evaporation and will also keep your plants from getting too much light. Third, you need to make sure that the reservoir has a way to drained. This will allow you to remove any excess water that your plants do not need.

There are many different types of reservoirs that you can use for the Kratky method. Some people use plastic containers, while others use glass jars. 

You can even use fish tanks if you want. The important thing is that you choose a reservoir that is big enough for your plants and has a way to be drained.


Assuming you are referring to the “lid” of a Kratky method setup, there are a few things to consider. 

  • First, you will need to make sure your lid is airtight. 
  • Second, you will need to make sure your lid has a hole in the center for the plant stem to go through. 
  • Third, you will need to make sure the lid is big enough to cover the entire top of your container.

As far as materials go, anything that can create an airtight seal and has a hole in the center will work for a Kratky method lid. 

Some people use plastic wrap, others use acrylic lids, and still others use mason jars with screw-on lids. It really just depends on what you have on hand and what you prefer.

Once you have your lid, simply place it on top of your container so that the hole in the center is lined up with the plant stem.

Make sure the edges are sealed tightly so that no air can escape. That’s it! Your Kratky method setup is now complete.

Net Pots

Net pots are plastic pots with a hole in the bottom and a small netting material surrounding the pot. 

The netting allows for adequate drainage while still providing support for the plant. Net pots are typically used to grow plants that have a small root system, such as herbs or succulents.

The holes in the bottom of the net pot allow for proper drainage, while the netting material provides support for the plant. 

The net pot is an important part of the Kratky method, as it allows for proper aeration and drainage of the roots.

Grow Medium

There are a variety of grow mediums that can be used with the Kratky method, but the most popular and effective options are hydroponic grow media or soilless mix.

Hydroponic grow media is any material that can be used to support plant roots in water. The three most common types of hydroponic grow media are expanded clay pellets, rockwool, and coco coir. 

All of these options are effective at supporting plant growth, but expanded clay pellets are the best option for beginners because they are easy to use and do not require frequent replacement like other options.

Soilless mix is another excellent option for the Kratky method. Soilless mix is a combination of peat moss, vermiculite, perlite, and sometimes coco coir. This mixture provides an ideal environment for plant roots and does not need to be replaced as often as other grow media.


When it comes to the Kratky method, there are a few key nutrients that your plants will need in order to thrive. First and foremost, they’ll need nitrogen. 

This is typically supplied in the form of ammonium sulfate, though other nitrogen sources can be used as well.

Phosphorus is also important for plant growth, and can be supplied through any number of phosphate-based fertilizers. 

Potassium is another nutrient that your plants will need, and this can be supplied through potassium sulfate or potassium chloride.

Finally, your plants will need access to calcium. This can be provided through limestone or gypsum. 

If you’re using the Kratky method to grow hydroponic plants, it’s important to make sure that your nutrient solution is properly balanced and that your plants are getting all the nutrients they need.

Measurement Tools

One of the most important aspects of successful gardening is using the proper measurement tools to track your progress. 

There are a variety of different measurement tools available, and each has its own set of benefits and drawbacks. In this section, we’ll take a look at some of the most popular measurement tools used by gardeners today.

One popular measurement tool is the soil moisture meter. This tool is designed to help you measure the moisture content of your soil. 

It’s a great way to ensure that your plants are getting enough water, and it can also help you avoid overwatering. Soil moisture meters come in both digital and analog models, and they range in price from around $10 to $50.

Another popular measurement tool is the pH test kit. This kit allows you to test the acidity or alkalinity of your soil. 

This information is important because it can help you determine which plants will thrive in your particular growing conditions. pH test kits usually cost between $15 and $30.

Finally, many gardeners use grow lights to measure the intensity of light in their grow room or greenhouse. 

Grow lights can be very expensive, but they’re essential for serious gardeners who want to get the most out of their plants. Luckily, there are a number of affordable grow lights on the market today that cost less than $100.

PH Control Kit

If you are growing plants in hydroponic systems, it is important to maintain the proper pH level in your water. The PH Control Kit from General Hydroponics includes everything you need to test and adjust the pH of your hydroponic solution. The kit includes a pH Test Kit, pH Up, and pH Down solutions, as well as a detailed instructional booklet.

Kratky Method for Hydroponics marijuana growing

Steps to Follow

If you’re looking to get started with the Kratky method, there are a few things you’ll need to do first. Here’s a quick overview of the steps you’ll need to follow:

  • Choose your plant. The Kratky method is well suited for a variety of plants, so take some time to choose the one that’s right for you.
  • Get a container. Any type of container will work for the Kratky method, but it’s important to make sure it has enough room for your plant to grow.
  • Fill your container with water. Be sure to leave enough room at the top of the container so that your plant has plenty of space to grow.
  • Add your plant. Gently place your plant in the water, making sure that the roots are fully submerged.
  • Wait and watch! The Kratky method is hands-off, so all you need to do now is wait and watch your plant grow!

Step 1:

To start the Kratky method, you will need to fill your container with water and add your nutrient solution. The ratio of water to nutrient solution should be about 30:1. 

Once you have added your nutrient solution, you will need to place your plant in the container. Make sure that the roots are submerged in the solution.

Step 2:

First, make sure your container is big enough. You’ll need at least 2 gallons per tomato plant.

Next, fill your container with a soilless mix. This could be something like perlite, vermiculite, or coco coir.

Then, add water to the mix until it’s saturated but not waterlogged. The mix should be wet but not dripping.

Now it’s time to plant your tomato seedlings! Gently remove them from their original containers and plant them in the soilless mix. Make sure to space them out evenly.

Once your seedlings are in the soil, give them a good watering. You can use a spray bottle or a watering can with a small nozzle. Avoid getting water on the leaves, as this could encourage disease.

Step 3:

In Step 3 of the Kratky Method, you will need to add more water to your container. The amount of water you will need to add will depend on the size of your container and the number of plants you are growing. Once you have added the appropriate amount of water, you will need to stir it gently until all of the roots are submerged.

Step 4:

If you’re growing plants in a water culture system, the fourth step is to add a support structure for your plants. 

This can be anything from a simple wooden frame to a more complex trellis system. The important thing is that the support structure is strong enough to hold up your plants as they grow.

Once you have your support structure in place, you’ll need to add some type of media for your plants to grow in. 

The most common type of media used in water culture systems is hydroton clay pellets. These pellets are lightweight and provide a good amount of aeration for your roots.

After you’ve added your media, it’s time to add water. You’ll want to fill the reservoir until the water level is just below the bottom of your plant pots. 

This will ensure that your roots always have access to moisture without being submerged.

Finally, you’ll need to add a light source for your plants. LED lights are a popular option because they emit very little heat and use very little electricity. Just be sure to position the light so that it evenly covers all of your plants.

Step 5:

The Kratky Method is a simple, yet effective way to grow plants without the need for a constant supply of water. In this guide, we will show you how to set up your own Kratky system and how to care for your plants.

Now it’s time to add your plants to the system. Be sure to gently remove them from their pots, taking care not to damage the roots. Place the plants in the reservoir, making sure that they are evenly spaced out. Once all of your plants are in the reservoir, top up with water until the reservoir is full.

Step 6:

The Kratky Method is a great way to grow plants without the need for a lot of water or nutrients. However, it is important to follow the instructions carefully in order to ensure that your plants are getting the care they need.

In the sixth and final step of the Kratky Method, you will need to add more water to your plants. 

This is because the roots of the plants will have grown and will be taking up more water. You should add enough water so that the plants are covered and there is a layer of water at the bottom of the container.

It is important to check on your plants regularly, especially during this stage, as they may need more or less water depending on the climate and temperature. 

If you notice that the leaves of your plant are wilting, this is an indication that they need more water. On the other hand, if you see that the leaves are turning yellow, this could mean that you are overwatering your plants.

Once you have added enough water, cover your container with a lid or plastic wrap and allow your plants to continue growing. 

Remember to check on them regularly and add more water as needed. With proper care, your plants should thrive and produce healthy fruits and vegetables for you to enjoy!

Kratky Method for Hydroponics cannabis growing

How does the Kratky Method work?

The Kratky method is a simple way to get started with hydroponics. It is a passive system, which means it does not require pumps or moving parts to work. The basic idea is to suspend your plants in a growing medium, such as gravel, with their roots in a nutrient-rich solution.

The Kratky method is named after Austrian horticulturist Bernard Kratky, who developed the technique in the 1930s. It is sometimes also called the non-circulating or static hydroponics method.

The main advantage of the Kratky method is that it is very simple and inexpensive to set up. All you need is a container, some growing medium, and a nutrient solution. This makes it an ideal choice for beginner hydroponic gardeners.

Another benefit of the Kratky method is that it is very low maintenance. Once your system is set up, there is no need to worry about pumps or other moving parts. The only thing you will need to do on a regular basis is top up your nutrient solution as it evaporates.

If you are looking for a simple and easy way to get started with hydroponics, then the Kratky method may be right for you!

Challenges and Disadvantages of the Kratky Method

As with any method of gardening, the Kratky Method has its own set of challenges and disadvantages that gardeners should be aware of. 

One of the main challenges is keeping the water level consistent. If the water level drops too low, the plant will start to wilt and may eventually die. 

Another challenge is controlling the temperature. The Kratky Method requires a warm environment, so if the temperature drops too low, the plants will not grow as well.

One disadvantage of the Kratky Method is that it is not suitable for all plants. Plants that require a lot of water will not do well in this method, as they will not be able to get enough water. Another disadvantage is that it can be difficult to set up. 

The Kratky Method requires special equipment and knowledge of how to set it up correctly, so it may not be suitable for everyone.

Other Variables are Hard to Control

It can be difficult to control variables such as temperature and humidity, which can impact the success of your Kratky method. 

If you’re not able to maintain a stable environment, your plants may suffer from stress or even die. Additionally, it’s important to carefully monitor the level of water in your reservoir, as too much or too little can also lead to problems.

Only Suitable for Small Plant Set-Up

The Kratky method is not suitable for large plant set-ups. It is best suited for small, home-based setups where space is limited. 

The main reason for this is that the Kratky method relies on a constant supply of fresh air to the roots of the plants, and this is not possible in a large set-up. 

Additionally, the Kratky method requires that the plants be placed close together in order to maximize the surface area of the roots exposed to air, and this is also not possible in a large set-up.

Larger Systems Cannot Be Built

Larger systems cannot be built using the Kratky Method due to the lack of a constant source of water and nutrients

The Kratky Method requires that a plant only have access to water and nutrients for a limited period of time, which is not possible with larger plants. 

Larger plants would require a constant supply of water and nutrients, which is not possible with the Kratky Method.

The Risk of Pest

Pests are a major risk to any hydroponic system, and the Kratky method is no exception. If not properly controlled, pests can quickly destroy a crop, and even spread to other plants in the system.

There are a number of different pests that can be found in hydroponic systems, but the most common are aphids, whiteflies, and mealybugs. 

These pests can be introduced to the system through infected plants, or by flying into the grow room from outside.

Once these pests get into the system, they will start to feed on the plants. This feeding can cause the plants to become weak and unhealthy, and eventually die. 

In some cases, the pests will also lay eggs on the plants, which can hatch and create an even bigger infestation.

The best way to prevent pests from getting into your hydroponic system is to practice strict hygiene. This means keeping your grow room clean and free of debris, and regularly inspecting your plants for signs of infestation. 

If you do find pests in your system, there are a number of different methods you can use to get rid of them. The most common methods are spraying with insecticides or using traps.

Water Quality Issues:

The Kratky method is an ideal way to grow plants without the need for a constant water source. However, because the plants are not constantly being watered, it is important to be aware of potential water quality issues that may arise.

One issue that can occur is the build-up of salts in the growing container. This can happen if the water used to fill the container is high in minerals, or if evaporation has occurred and concentrated the minerals in the remaining water. 

If this happens, it can lead to poor plant growth and even death. To avoid this problem, it is important to use distilled or reverse osmosis water when filling the container.

Another potential issue is the growth of algae or other aquatic organisms in the container. This can happen if there is too much light entering the container or if the water temperature is too warm. 

Algae growth can compete with plants for nutrients and space, and can also lead to poor plant growth. To avoid this problem, it is important to keep the container out of direct sunlight and to maintain a cool water temperature.

What Types of Plants Can You Grow with the Kratky Hydroponic Method?

The Kratky method is a great way to grow many different types of plants. Some of the most popular plants to grow with this method include lettuce, tomatoes, peppers, and cucumbers. 

Herbs like basil and oregano also do well with this method. You can even grow flowers like sunflowers and zinnias. The possibilities are endless!


The Kratky Method is a simple, efficient way to grow plants without the need for a constant supply of water. It was developed by Dr. Bernhard Kratky, a professor of horticulture at the University of Hawaii. The method is well suited for growing crops in arid climates, or for those who want to reduce their water usage.

The Kratky Method involves suspending a plant in a container filled with just enough water to cover the roots. The plant is then left to grow undisturbed until it reaches maturity. There is no need to water the plant during this time, as the roots will access the water as needed.

The main advantage of the Kratky Method is its simplicity. There is no need for complex equipment or Constant vigilance when using this method. Additionally, it is an extremely efficient way to use water, as evaporation is minimized and there is no runoff.

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