The Kratky Method: How To Grow Food Almost Automatically

The Kratky Method

Although I already think that hydroponics is one of the most interesting, simple, and productive gardening methods out there, what continues to surprise me is the amount of innovation that happens in the field. There are so many different hydroponic systems out there and they seem to be limited only by our imagination.

Not too long ago I was looking for more ways to experiment with my deep water culture systems, including building a very simple hydroponics for kids project. I wanted to keep the system as simple as possible while making sure it still produced a healthy plant.

Enter the Kratky Method.​

What Is The Kratky Method?

Let’s start off with my video overview of the Kratky Method:

Because hydroponics grows plants without soil, there are often a lot of moving parts in a hydroponic system: pumps, wicks, airstones…and the electricity to power them all. Don’t get me wrong – this is part of what I LOVE about hydroponics – but sometimes you just want to keep it simple.

This is where the Kratky method shines. It’s a technique that allows you to grow hydroponically without electricity, pumps, or wicks of any kind. In fact, you don’t even have to change your reservoir or add nutrients. It’s as close to a completely “hands off” growing technique as I’ve ever seen.

How to Build a Kratky System

This is a really fun method to mess around with – give it a shot! Once you understand the basic principles, it’s probably the easiest and cheapest method you could ever use to grow hydroponically.

Here’s everything you need to get started with the Kratky method:

Part List  Details Link

5 Gallon Bucket

See Prices

3″ Net Pots

See Prices

3″ Hole Bit

See Prices

Growing Media

See Prices

Nutrients

See Prices

ph Control Kit

See Prices

PPM Meter

See Prices

How The Kratky Method Works In Detail

In a traditional deep water culture setup, you typically have your plant in a net pot with growing medium and you place it in a reservoir. Then you fill the reservoir with nutrient solution up to a certain point, making sure it doesn’t touch the net pot.

The airstone that you add to your system will create bubbles that pop at the surface of the water, hitting your growing media and feeding your plant’s young root system. As the roots grow, they’ll eventually hit the surface of the water and growth will explode from there on out.

With the Kratky Method, you actually fill your reservoir with properly conditioned water further, making sure to cover the bottom third of the net pot with water. The reason? Without an airstone, your plants will need water at the start of their lives, and this technique ensures they’ll never dry out as your growing media is constantly wet.

As the plant continues to grow, it will use water and the water level will decline – but your plant’s roots will have descended into the nutrient solution by that time.

You might be wondering, “Aren’t airstones used for more than just wetting the growing media in the seedling phase?” You’re right – this is where the beauty of the Kratky Method starts to shine. Because you are not refilling your reservoir, your plants will keep using up water and exposing more and more of their root systems to the air, which will ensure your plants get enough oxygen to survive and thrive.

Potential Problems With The Kratky Method

Like any system, there are some flaws and considerations you should be aware of if you want to make sure you have a successful grow.

Good for Leafy Greens Only – This is designed to be a simple, hands-off method. That means it can’t really account for the increased nutrient and water requirements of plants that bear fruit. Use this for leafy greens like lettuce, spinach, etc – not fruiting plants like tomatoes, cucumbers, etc.

Pests – Because your nutrient solution will be still (because you’re not using an airstone), it can draw the attention of pests, namely mosquitoes. To avoid this, make sure that the reservoir is protected from any type of bug or pest, while allowing some oxygen and air to flow in as well.

Water Quality – You are not going to be replacing or adjusting the water level in your reservoir, so it’s important to start with very high quality water. If you’re going with the Kratky Method, I would recommend reverse osmosis or filtered water – get your PPM as low as possible so you avoid a dangerous concentration of salts.

Watch Your pH – If you’re new to the method, you may want to pick up a pH pen and test it every day. Once you get the hang of how to prepare your nutrient reservoir for the plant that you’re growing, you can leave the system to do its job!

*You can find the original paper about the Kratky method here. Be forewarned, it gets a little technical!

SHARE THIS POST
A small white house displays a wall completely covered by ivy.

Gardening Tips

Myth or Truth: Will Ivy Destroy the Exterior of Your Home?

Thinking of planting some ivy or buying a home with ivy-covered walls? Have you heard horror stories about aggressive climbing vines burrowing into bricks and siding? In this article, landscape designer Liz Jaros examines the controversy surrounding exterior ivy, takes a closer look at the most common varieties, and offers suggestions for preventing damage to your home.

close up of a branch laden with bright green leaves and ripening fruit.

Gardening Tips

What Trees Work Best in a Permaculture Garden?

Are you starting a permaculture garden and wondering what trees to grow? Permaculture is a great way to create a sustainable garden in your own yard! You can grow a wide variety of plants and enjoy an edible landscape. In this article, gardening enthusiast Liessa Bowen will discuss the types of trees that work wonderfully in a permaculture garden.

Drifts of golden yellow black-eyed susans and pink coneflowers bloom in a lush border.

Gardening Tips

11 Tips for a Native Garden with Curb Appeal

Some gardeners are afraid to grow a native plant garden, fearing it will look untidy. There are many ways you can help your garden look great, both up close and from a distance. In this article, gardening expert Liessa Bowen discusses 15 tips to help your native plant garden thrive and look spectacular in the process!