Hydroponics has become a popular and exciting way to grow your own food.
As more people get into it, more people are finding that it’s not quite as simple as starting a vegetable garden outside.
There are lots of different components with most hydroponic systems, such as air and water pumps, meters for monitoring, filters, and reservoirs, to name only a few of the basic necessities.
Traditional hydroponics can also take up a lot of space.
For someone looking to grow only a few plants, maybe some lettuce or some herbs, a complex setup just isn’t appealing. The Solution?
The Kratky method. This passive, low-cost, and easy-to-start hydroponics setup is perfect for the hobbyist hydroponics gardener.
This article will guide you through a hydroponic method that doesn’t require all this extra stuff.
We will discuss and explain What is Kratky method is and How Does it Work?
After explaining what it is, we’ll guide you through setting up your own Kratky “non-circulating” hydroponics system in few easy steps.
Table of Contents
What is the Kratky Method?
The Kratky Method was developed by Bernard A. Kratky, a University of Hawaii professor. This method was designed to be a passive way to grow plants.
By passive, I mean that you can essentially set it and forget it. Unlike more complex systems, once you set everything up, no maintenance is required.
The only maintenance you will need to perform is ensuring that there isn’t too much water, that roots get no air or that the water is too low for the roots to reach.
You don’t need expensive hydroponic air pumps to move water or supply air or an extra reservoir to feed your plants. All you need is a container, something to hold your plants, and your plants.
With traditional hydroponics, there is a much larger volume of water and nutrients, which must be constantly aerated.
This aeration prevents a large number of problems that are caused by having a lot of plants growing in a system together.
Pumps are also required to move water and/or to circulate the water to keep all the nutrients suspended.
These pumps require a lot of electricity, which obviously increases the costs you must pay to grow your plants.
You also need to maintain these pumps and all the connections between them, costing you time as well.
By not using pumps and aerators required by complex hydroponics systems, you save yourself the money from buying these and the time from not having to maintain them.
This method allows you to grow hydroponically without all the expensive equipment; you don’t even need electricity!
Setting Up a Small Kratky Hydroponics System
To use the Kratky method, you need a few basic materials:
- Container with a lid that can be cut
- A seed or young plant
- Hydroponic nutrients (here how to make your own)
- A pH testing kit
- Net pot
- Growing Media – rockwool or hydroton
To start, you need to first decide what you want to grow. This is important because what you grow will determine what kind of container you will need.
- If you’re growing lettuce, basil, or anything smaller, a large mason jar or 2-liter soda bottle would work fine.
- If you want to grow something larger, such as a tomato or pepper plant, you would want something like a 5-gallon bucket.
Next, you want to add your water and nutrients to your container. A great nutrient kit to use would be the General Hydroponics Starter kit.
This kit comes with everything you will need for this system, from nutrients to your pH kit.
Simply follow the instructions in the kit to create the perfect solution for any plants you are growing.
This kit will also help you set your pH correctly, which is important for the health of your plants.
Now you simply need to add your plants.
If growing from seed, soak your rockwool cube and place the seed in the pre-drilled hole.
Your seed will germinate in here and grow roots down into your container
Make sure to keep your rockwool cube moist while germinating your seed(s).
If the cube dries out, your seed will die, or your seedling will never grow large enough.
If you already have a young plant, remove any dirt from around the roots by washing it off.
Then place the bare roots in a net pot so that the roots are coming out of the bottom of the pot.
Now cover the roots with hydroton.
Above is an example of how the roots should look after putting a plant through the net pot with hydroton on top.
This image is actually showing a mature plant, but the concept is the same.
Let it grow!
Now that your plant is in the container, you’re done!
All you need to do now is wait for the plant to grow until you want to harvest it.
If your plant uses up all the water before it’s ready to harvest, just add more water and make sure to add nutrients too!
How The Kratky Method Of Hydroponics Works?
This might seem almost too simple, that it’s surprising it works so well. Let’s discuss how and why the Kratky method works.
As we all know, plants need water to survive; they also need air and nutrients as well.
The Kratky method provides all of these in the simplest way possible.
The roots naturally search for water and nutrients, and so will grow downwards into the solution.
As the plant takes up water, which we add nutrients to, there is more air in the container.
As more air space exists in the container, this provides oxygen to the roots, which plants need to perform photosynthesis.
The more area of the roots exposed to water, the greater amount of oxygen they receive.
If using a larger container, there is a large amount of both air and nutrient solution available to plants.
Which is what makes it possible to grow a giant tomato plant in a 5-gallon bucket.
The Kratky method works as well as it does because all of the requirements that determine plant growth are met and exceeded.
Problems and considerations of the Kratky method
Although this hydroponic method is great for certain situations, there are some issues with using this method.
- If you want to grow a larger plant, such as a tomato plant, there is some more maintenance. The water will drain much faster and you need to ensure the plant gets enough nutrition.
- Because there isn’t a lot of air being added to the water, this may attract pests that are drawn to still water, such as mosquitoes.
- Because the water won’t be replaced or adjusted often, if at all, you want to make sure to start with clean water. At least filtering your water before adding will prevent dangerously high concentrations of salts that may harm your plants
- Without adding oxygen or circulation to the water, this method only works best for small plants.
More plants or larger plants in a system this size would require additional oxygen and more water and nutrients than would be practical.
The Kratky method is an excellent way to get started in hydroponics.
If you’re a beginner or just want to grow a plant or two in a mason jar, then this method is exactly what you want.
Even just as a method to learn how hydroponics (and even aquaponics) works, this would be a great choice.
If you want to grow anything on a larger scale or grow large plants, or vining crops, then the Kratky method is not for you.
It’s great to learn from and very useful as an educational tool, but for serious production of food or herbs, there are much better options.
In conclusion, give it a try! The worst thing that can happen is you’ll learn something.
Lindsey Hyland grew up in Arizona where she studied at the University of Arizona’s Controlled Environment Agriculture Center. She continued her gardening education by working on organic farms in both rural and urban settings. She started UrbanOrganicYield.com to share gardening tips and tactics. She’s happy to talk about succulents and houseplants or vegetables and herbs – or just about anything in a backyard garden or hydroponics garden.