Hydroponic lettuce kratky method

The Kratky Method of Hydroponic Gardening

  • Twitter
  • Facebook
  • Pinterest

Hydroponic systems come in all shapes in sizes. They all have a little bit in common, but the Kratky method of hydroponics is really apart from the rest. This simple hydroponic method gives you a system that is completely passive, needing no electricity.

Is a Kratky hydroponic system for you? Here’s what you need to know about the Kratky method of hydroponics.

First, Why Is It Called The Kratky Method?

The Kratky method was developed by Benard Kratky, a Researcher Emeritus at the University of Hawaii. He has been doing research on passive hydroponics for decades, conducting experiments, and has released many publications on the subject.

How The Kratky Method of Hydroponics Works

There are several ways to set up a Kratky hydroponic system, though they all work under the same premise. Kratky hydroponic systems do not use any electricity, so there are no air or water pumps. As the plant takes in the nutrient solution, it drops the water level in the reservoir providing air to the root system.

The Kratky Method Of Hydroponic Gardening

Depending on the type of plant and the size of the reservoir, the plant may be ready for harvest when the nutrients are running out. If the plant’s not ready for harvest, more nutrients can be added as needed.

When more water is added to the reservoir it’s important to leave an unfilled area open for the plant roots to breathe. Filling the reservoir, and submerging most of the root system in the nutrient solution, will drown the plant.

What Plants Grow Well In Kratky Hydroponic Systems?

Any plant that is not a root vegetable can be grown using the Kratky Method of hydroponics. Some just grow better than others.

Leafy greens like lettuce and herbs grow the best in Kratky systems. Fruiting plants can be a little more difficult to grow. They need to be in larger systems as they will use more nutrients and require more air at the root system. The nutrients will also need to be switched over for the flowering and fruiting stages.

The Advantages Of Using The Kratky Method

Now that you know what the Kratky method of hydroponic is and how a Kratky system works, let’s discuss the benefits of using this method in your hydroponic garden…

No electricity needed-The main benefit of the Kratky hydroponic system is that it doesn’t require electricity, making it the perfect hydroponic system for those in areas where electricity is not available. Survivalists, those living in remote areas, and people living in underdeveloped areas have been able to grow fresh produce where they otherwise might not have had the option of a garden.

Minimal maintenance– Those with access to electricity can still benefit from using the Kratky Method. The nature of how this hydroponic system operates makes it ideal for those that are looking for a hands-off hydroponic system. The only thing to monitor is the nutrient level, adding more when the system is running out.

Minimal cost– Another benefit to using a Kratky hydroponic system, is the lower initial cost and cost of maintenance. Since this system doesn’t need pumps, hoses, and timers, you not only save money by not having to purchase these items, but you do not have to worry about the cost of repairing or replacing parts of this hydroponic system.

hydroponic lettuce

The Disadvantages Of Using The Kratky Method

While there are many benefits to a Kratky hydroponic system there are also several drawbacks to using this method of hydroponics.

Best when covered–  The Kratky Method of hydroponics is harder to control when your system is outdoors in the elements. This type of hydroponic system works better indoors, in a greenhouse, or covered area.

It’s important to not let rainwater get into your reservoir, which can happen if it were out in the elements. Rainwater can dilute the nutrient solution and alter its pH.

Larger plants grow slower– In my experience, larger plants grown using the Kratky Method have grown slower compared to those grown using other hydroponic methods. Plants really benefit from added oxygen to the root zone.

Stagnant water– Stagnant water can be an attractant for pests. Make sure the lid of your system closes well and there isn’t a lot of room for pests to get into the reservoir.

With stagnant water at warm temperatures, root rot can occur. For those larger fruiting plants that need their nutrient tanks refilled, I recommend adding only enough nutrient solution to cover 25% of the root system, leaving the rest in an open-air gap.

Need quality water to start– Ideally you should always start with quality water. It’s even more important when using the Kratky Method. Salt buildup and pH issues can stunt your plants.

Harder to control temperature– With the way Kratky systems are built it can be hard to control the temperature. Covering or burying the reservoir can reduce temperature fluctuations.


The Kratky Method of hydroponics can be a great option for many people, especially those without access to electricity or those looking for a low-maintenance hydroponic system. They work great for growing leafy greens, and with a little more work, can grow some fruiting vegetables as well.

2 Answers

Leave a Reply

Your email address will not be published.
Required fields are marked *