Hydroton: A Guide to Using Clay Pebbles in Hydroponics

Hydroton: A Guide to Using Clay Pebbles in Hydroponics

Hydroton is becoming a popular gardening alternative to soil as it has numerous benefits. One of these benefits is improving the drainage for your plants so that their roots don’t sit in water, which would prevent them from growing healthily. But, how do you start using these clay pebbles in your garden?

You can start using hydroton in your garden by adding it to your soil. You can also use these clay pebbles hydroponically for plants that you’re growing in water. When growing plants from seeds or cuttings, hydroton can be a beneficial growing medium.

In this article, I’ll explore everything you need to know about hydroton, how to use it in various ways, as well as what to know about its pros and cons. Let’s start with what hydroton actually is and why it works to improve your gardening tasks. 

What Is Hydroton?

What Is Hydroton?

Hyroton is the name for expanded clay pebbles that have been heated so that they can be used as growing media for plants. Since they’re highly porous, they transmit the water, nutrients, and oxygen that plants need to survive, just remember that they don’t contain these though and that you must provide them.

To make hydroton, clay is heated to extremely high temperatures so that the clay balls fill up with air bubbles. These clay pebbles are small in size, which makes them versatile to use in the garden, whether in pots or directly in the ground.

Hydroton can be used in combination with soil or alone to replace soil entirely. If your potting soil is in need of drainage, you can apply a layer of hydroton underneath your soil. Essentially, there are different ways in which you can use hydroton effectively. 

One of the best things about using hydroton instead of soil is that it enables you to check your plant roots without disturbing them or pulling them out of the soil in which they’re growing. 

If you’re growing hydroponically, you can still use hydroton. However, since it doesn’t hold water, you will need to ensure that your hydroponic system will irrigate your plants regularly if they require frequent watering, otherwise, they could dry out.

If you’ve heard of hydroton and LECA, you might wonder if they’re the same thing. They are! Hydroton is sometimes referred to as LECA, which stands for lightweight expanded clay aggregate. 

How to Use Hydroton in Hydroponics 

How to Use Hydroton in Hydroponics 

There are plenty of good reasons why you should use hydroton in hydroponics, such as 

  • Hydroton maintains moisture—this can be beneficial if your area doesn’t get a lot of water as you won’t have to water the plants as much 
  • Hydroton drains well—this prevents your plants from being drenched in water or getting too much water, which could result in root rot, usually a fatal condition for plants 
  • Hydroton enhances air circulation—since they’re porous, clay pebbles help to enhance aeration, something that’s also beneficial for the soil as it prevents it from becoming compacted 

Tips for using hydroton in hydroponics:

  • Make sure you monitor your plants, they can dry out quickly because of how the clay pebbles drain water
  • The pebbles can make their way into pumps and clog them, so be careful of this when using hydroton in water
  • Rinse the pebbles before using them in hydroponic gardening so that debris doesn’t clog your filters

You can use clay pebbles when growing plants from seeds. You should fill small net pots halfway with the hydroton and then cover the seeds with additional hydroton.

When the seedlings are ready, you can transplant them into your hydroponic system. From time to time, it’s good to remove and rinse the pebbles so that they stay sterile and hygienic. 

If you’re just getting started with hydroponics, you should read our guide on, DIY hydroponics at your home

How to Use Hydroton in Soil

How to Use Hydroton in Soil

Although the thought of using hydroton might seem overwhelming at first, it will soon become easy to use. How you use hydroton will differ depending on the method you choose, which will be based on what you need for your plants. 

  • If your plants need good drainage, they will benefit from mixing hydroton with the soil in a 30:7% ratio. This will ensure that the medium will maintain some water instead of draining it too much. You should, therefore, consider how much drainage your soil needs before adding hydroton to your soil.
  • If you’re growing plants in containers or pots, you can also add a layer of clay pebbles to the bottom of the container. This will ensure that your pots get enough drainage and it works well for indoor plants.
  • Although hydroton helps to drain excess water so that plants don’t sit in water, you can also use it to maintain water. To do this, crush the clay pebbles before mixing them with the soil.

Benefits of using hydroton in soil include

  • It can amend your soil. By improving your soil’s drainage with the use of hydroton, you won’t have to make use of more complicated methods to boost drainage. However, it’s important to remember that you can’t rely on clay pebbles to give your soil nutrients as it doesn’t contain any. 
  • Clay pebbles are pH neutral, so you don’t need to worry that they’ll disrupt your soil’s pH. This makes them easy to use with many different plants, regardless of their soil pH requirements. 

How to Use Hydroton in Propagation 

How to Use Hydroton in Propagation 

To propagate your plants so you can grow new ones, you can make use of hydroton as a growing medium. Let’s explore how to use hydroton when propagating plants by seed or via cuttings. 

Growing Plants From Seeds

To grow seeds in soil, all you have to do is fill a container with pebbles (either crushed or whole) and potting soil. Then, scatter your seeds on top. Make sure you put the container in a sunny area of the home so that the seeds are warm enough to germinate. 

If you’re growing plants in hydroponics, you can grow seeds with hydroton by placing the seeds on a net cup that’s filled with clay pebbles in water. This prevents the seeds from being too immersed in water, which would reduce the chance of them taking root. 

Growing Plants From Cuttings 

You can easily propagate your plant cuttings in hydroton. To do this, you should follow these steps:

  1. Put about one inch (2.54 cm) of clay pebbles in a glass container. 
  2. Put your plant cutting in the container, then add more pebbles so that they help the cutting to remain securely in place to take root. 
  3. Add water to the container. It should be filled to approximately an inch (2.54 cm) below the top of the pebbles.  
  4. Cuttings need to remain moist, so make sure you keep an eye on the water in the container as it will evaporate.

Benefits of using hydroton to propagate plants include:

  • Ease of use—you can easily propagate plants in pebbles, even if you’re a beginner gardener, and it can encourage seed germination.
  • Reusable—you can reuse the pebbles after you’ve transplanted the plants into a container or the ground 

Hydroton Cost and Expenses 

Hydroton Cost and Expenses 

You will have to figure out how much hydroton you need for your plants. If you’re using a net pot or you’re putting a plant cutting in a glass container to let it grow, you will have to fill it all the way to the top. How much you’ll need will depend on the size of the container that you’re using.

Generally, though, one pound (0.45 kg) of hydroton clay pebbles will be enough for one square foot, at a depth of approximately two inches (5.08 cm). 

You can expect to pay approximately $16 for four liters (1 gallon) and $19 for 10 liters (2.6 gallons) for hydroton that’s available on Amazon. However, you can also purchase hydroton from other online sources, as well as from your local nursery.

Hydroton is worth using when you consider that you can reuse the clay pebbles. So, even if they’re a bit expensive upfront, they will last for a long time without decomposing, which makes them value for money. Between uses, you just have to rinse the pebbles with water.

Crushing the pebbles will save you some money but if you have a large container, you could end up crushing lots of pebbles to get the right amount, so it might not be worth it. 

When doing this, bear in mind that when hydroton is crushed it will preserve more moisture in the soil. This isn’t going to be the correct growing situation for all types of plants and should be avoided if you’re growing plants that don’t need a lot of water. 

How to Maintain Hydroton Clay

How to Maintain Hydroton Clay

Before you use hydroton in your gardening, you will need to prepare it properly. You also need to maintain it. Here are some things you should bear in mind so that you get the most benefit from using clay pebbles 

  • Check for white residue on your hydroton clay pebbles. This indicates that the minerals in your water are accumulating on the pebbles. You should flush the pebbles. 
  • Always rinse the hydroton clay balls before use. You can put them in a bucket of water to wash them well. It’s also good to soak them to remove debris that accumulates in their pores.
  • Supplement your plants with nutrients. Clay pebbles don’t have any nutrients that they can impart to the plants you’re growing in them. 
  • Always rinse the hydroton balls if you’ve stopped using them for one plant and want to reuse them for another plant. 
  • Since pebbles are sterile, they ensure that your plants won’t become affected by bacteria. However, your pebbles can attract fungi, which is why some hydroponic growers will wash them in household solutions or cleaning agents specifically tailored to hydroponics. 
  • These pebbles don’t remain wet, they can dry out. This is something to monitor and you must make sure that you water the pebbles regularly.
  • To ensure that your seeds get enough moisture to germinate, you should use crushed clay pebbles. This makes the pores on the pebbles smaller and increases how much water they maintain for the seeds.

If you’re still unsure of whether to use hydroton in soil or hydroponics, learning more about these different growing mediums can help. Read our guide on hydroponics vs. soil for indoor gardens for more information. 


If you want to start using hydroton in your garden, you can do so in various ways, such as by propagating seeds and cuttings or adding clay pebbles to your current soil. Hydroton has various benefits for plants, it

  • Enhances the soil’s drainage so the plant roots don’t sit in water 
  • Is pH neutral, so it won’t negatively affect your plants that need acidic or alkaline soil
  • Can be crushed to maintain enough soil moisture 
  • Can be reused, which makes it worth purchasing 

About The Author

Gina Harper grew up dreaming about farms and growing her own food. She began an urban garden to feed herself and turned it into an incredible hobby. Gina is here to teach you everything from raised beds to container gardening, how to keep plants alive and well in a smoggy city, and the works. It’s time that we carve our own piece of green earth and reap what we sow—she’s here to help you with that.