Hydroton (LECA) Preparation Guide | Will Hydroton Sink?

Hydroton or lightweight expanded clay aggregate (LECA) is a versatile and reusable growing medium for plants. Hydroponic, aquaponic and high drainange plant growers, such as orchids, will frequently use hydroton instead of soil.

So how do we get hydroton to sink?

Hydroton needs to soak in water ahead of time in order to sink. Soaking hydroton in water will also wash the clay dust that can build up from the balls rubbing against each other. As the hydroton soaks, the balls will retain more water over time and the air pockets will start to fill with water allowing the balls to sink. Ideally you should soak hydroton anywhere from 24 to 48 hours.

Here is a quick video walk through of soaking hydroton and how to get floating hydroton to sink:

Before we continue with how we can soak or crush hydroton to help it sink, let’s quickly cover what hydroton is made of and used for.

What Is Hydroton?

Hydrtoton, also known as light expanded clay aggregate (LECA), is a growing medium composed of expanded clay pebbles.

Hydroton is a popular growing medium since it is porous, inert, and reusable. Growing mediums are typically used in place of soil for indoor or hydroponic gardening.

Instead of soil providing the nutrients, typically plants grown in hydroton will absorb their nutrients from a nutrient solution. The hydroton simply holds the plants in place and provides a foundation for the plants to grow taller.

I purchased a 10L bag of hydroton on Amazon since it was relatively cheap for how much hydroton you receive.

Although there are a lot of benefits to using hydroton, there are also some common issues to be aware of.

Challenges Or Issues With Hydroton

There are many beneficial reasons to choose hydroton as a growing medium.

However, the fact that hydroton floats can cause both minor and major issues.

Just image if you are germinating a seedling or transplanting a cutting in hydroton and you fill your container with water. The balls that are buoyant will float to the top which can cause your plant to sink to the bottom of the water.

As the water level decreases, your plant will be underneath all the hydroton balls. This can kill your plant!

Although this is a common and annoying issue with hydroton – overall it’s one of the best growing mediums to use. So let’s cover how to resolve this issue since the benefits of hydroton really do outweigh the cons.

Soaking Hydroton In Water

Soaking hydroton in water is a helpful step in preventing the majority of hydroton from floating whenever you decide to water your plants.

Hydroton is a porous material which means there are a lot of air pockets within the clay balls. So when given a proper soak, the hydroton will absorb the water and eventually sink.

Here are the steps to soak hydroton:

  1. Fill a container full of water (I just used tap water)
  2. Place the hydroton inside the water container
  3. Wait 24-48 hours
  4. Remove the hydroton that’s still floating
  5. Use the remaining hydroton that sank for your potted plant

Benefits Of Soaking Hydroton In Water

Pre-soaking the hydroton will help your seedlings or plants transfer successfully into a new pot full of hydroton since they will be surrounded by balls that can slowly release water onto the roots.

Not to mention the hydroton will develop air pockets which provides the oxygen that the roots also need in order to grow in hydroponics or a water based environment.

Crushing Floating Hydroton

A good way to get hydroton to sink is by simply crushing the balls into tinier pieces.

The air gaps within the balls cause the hydroton to naturally float. So by breaking the ball apart you are removing those air gaps.

From the video above, I take the hydroton that will not sink and crush them with a hammer. You can see from the photo below that this will release any air pockets that were causing the hydroton to float.

crushed hydroton LECA balls

Another benefit of crushing hydroton is to increase the water retention of the medium which is ideal for seed germination.

Crushed hydroton is also commonly used for plants or growing areas where water retention is preferred. Unlike perlite which helps create porous gaps in the soil, crushed hydroton will act more like vermiculite as it absorbs and slowly releases moisture.

How To Use Hydroton

Hydroton is a growing medium so instead of soil you will be using hydroton in its place.

Typically this means that you will need to provide your plants with supplemental nutrients through nutrient solutions or liquid fertilizers.

Below are my jalapeno pepper plants growing in a 5 gallon bucket full of nutrient solution with hydroton as the growng medium. You can see how the roots are grabbing onto the hydroton so that the plants can continue to grow taller.

Jalapeno pepper plants growing in hydroton hydroponics

If you are new to the world of hydroponics or growing plants without soil then I recommend using General Hydroponics Flora Series since its very simple to create nutrient solutions. The 3 bottles will allow you to adjust the nutrients you provide the plants in order to encourage plant growth or flowering.

Frequently Asked Questions

Q: Can I use hydroton for orchids?

A: Hydroton is a great growing medium for orchids. Hydroton can be mixed with the potting soil or the orchid can be placed in a hydroponic system. Orchids can grow in drain and flood, also known as ebb and flow, or deep water culture systems since these systems allow for longer growth plants.

Q: Where can I buy hydroton?

A: I purchased my hydroton off Amazon since this 10L bag is usually priced very well. However, hydroton can usually be found at local hydroponic and gardening centers.

Q: What are hydroton clay pebbles?

A: Hydrtoton, also known as light expanded clay aggregate (LECA), is a growing medium composed of expanded clay pebbles. This growing medium is used as a foundation for the plants roots so the plants can continue to grow taller. Hydroton is inert, porous, and reusable so many growers prefer hydroton over other growing mediums.

Q: Can you reuse hydroton?

A: Hydroton is reusable. Hydroton just needs to be rinsed or soaked in water and allowed to dry thoroughly. Usually the biomaterial from the previous plants will dry out and fall off if given a few days to dry out in the sun.

Q: Can I start seeds directly in hydrton?

A: I start seeds directly in hydroton instead of using starter plugs such as rockwool or growing trays. Here is an in-depth guide on starting and germinating seeds in hydroton. The huge benefit to starting seeds directly in hydroton is that you will not need to transplant your delicate seedlings from their starter plugs into hydroton.


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