LECA (Hydroton): How to Use Expanded Clay Pebbles in Hydroponics

LECA is the acronym for Lightweight Expanded Clay Aggregate. It is a well-known Hydroton used as a medium for hydroponic gardening.

These substances behave similarly to the other hydroponic media, such as coco coir, peat moss, perlite, pumice, and vermiculite.

Hydroponic media have a higher water retention capacity and a better drainage system.

This is why plant roots can successfully continue their respiration process in the system.

Related post: Various Types of Hydroponic Growing Mediums to Use

What is LECA?


LECA is a Hydroton because it is a product of enlarged baked clay pebbles.

It is a lightweight growing medium that acts similar to soil, but the characteristics differ.

For example, LECA does not contain any nutrients like soil, but it has better drainage and a higher retention capacity.

It is a collection of baked clay balls. These clay balls expand when they are soaked in water.

Hydroponic farmers use these soaked clay balls to grow houseplants or hydroponic crops.

You must supply nutrient solutions to supply essential nutrients to the plants if you use these clay balls solely as the medium.

To make this product, clay is inserted in a rotary kiln and then heated to 2190-degree Fahrenheit.

This high temperature will produce tiny bubbles and slowly make them light. It also gives them a pseudo-circular shape.

Why Should You Use LECA for Growing Plants?

A grower may receive a plethora of advantages by using LECA. We will briefly discuss the most important advantages that you can get from these clay balls.

Water Retention Capacity in LECA


Water is an important factor that controls vegetative growth. Under-watering can inhibit the growth of the plants, while over-watering can cause root rot.

In fact, root rotting may take place if the houseplants stay in water for a longer period.

This is a common scenario in clayey soils because clay soils have poor drainage systems and retain moisture for too long. 

If your potting medium or garden soil is clayey, you can use LECA to improve the condition.

These materials are often used with other minerals like vermiculite, pumice, or perlite in a hydroponic system.

Growing plants using LECA in hydroponic helps the plants to absorb water when they are thirsty.

Better Root Systems By Using Expanded Clay Pellets

Plant roots start rotting when they stay submerged in water and deprived of oxygen.

Root respiration is a vital physiological process that keeps plants fresh. In hydroponic systems, people make mistakes by choosing the wrong mediums.

They either choose the materials that have high water holding capacity and poor drainage.

LECA can prevent this problem because it has larger pores and absorbs water for a long period.

Even the addition of more water does not damage the roots. These aggregated clay pellets have larger air gaps between them and supply oxygen to the roots. 

Less Pest Infestation


Bugs attack the houseplants when they are in unfavorable condition and start rotting. A common scenario is root rot.

They the plants are over-watered, roots start rotting, and bugs are attracted to them.

Also, growing mediums like soil may contain microbes that can damage plants.

However, LECA is not active and does not contain microorganisms. So, you do not have to worry about pest infestation in this case.

If you notice insects in the roots, we suggest using LECA or other growing media to eliminate them.

Reusable Materials

Even the nutrient content in soil depletes over time. So, gardeners must use new soil while repotting the plant.

As a result, old soils must be dumped off or kept fallow and mixed with organic material to make them productive again. This is a long-term process.

On the other hand, LECA is reusable, so you do not worry about its nutrient content or quality.

If you notice that the balls are getting dirty, you should wash them properly and add a new solution.

Limitations of LECA


Despite the advantages, there are a few limitations that can be really frustrating.

  • Very expensive than other hydroponic growing rocks.
  • You must fertilize to supply nutrients for the plant.
  • LECA is an inert substance. So, monitor the pH of the solution to maintain a neutral pH.

Transfer Your Plants to LECA

  1. Firstly, loosen the soil around the plant.

    Many gardeners immediately take out the plants from the garden soil, but removing a plant is the wrong way.

    If the soil is too dry and hard, add water and make it soft. Slowly insert your hands and take the plant out of it.

  2. Once the plant is out of the soil, spray water to the roots to remove the remaining dirt.

    In this step, use tap water and rub the roots gently and avoid causing any damages.

  3. Now, you should prepare the pots by adding LECA balls. Fill the bottom of the container with them.

    Then place the plant. Roots must sit on top of the balls in this step. Now add more balls and fill the container.

  4. Add nutrient solution and check the pH level of the water, which should be between 5.5-6.5.

    You can use a testing kit or other items from reliable brands. 

Is It Good to Mix LECA with Soil?

Many growers often become confused about it. They do not understand whether they should use LECA solely or mix it with soil.

Remember that these pellets are inert substances and do not contain any nutrients like soil.

Therefore, if you decide to use these pellets only as of the mixture, then you must add nutrients or hydroponics fertilizer.

That’s why LECA is used in aquariums or hydroponics gardening. Klayton is another substance that can be used alternatively to LECA [1].

These clay pellets can be mixed with potting soils because they can supply moisture when the soil becomes dry.

LECA has capillary pores in it, and we know that capillary force is stronger than gravitational force.

Thus, because of having capillary pores inside the balls, they can retain water against the force of gravity.

Also, they will supply air and improve the structure of the heavy clay soils. 


What are the benefits of LECA (Hydroton)?

You can get manifold benefits from this Hydroton.

Most importantly, you will not have to worry about watering/root rot.

What is Hydroton (LECA) used for?

LECA is mainly used as a hydroponic medium.

Which is better, Hydroton vs. Perlite?

Both Hydroton and Perlite rocks improve the aeration of the growing medium.

However, hydroton is better as this material soaks moisture and retains it.

Is Hydroton the same as LECA?

Hydroton and LECA are the same. They are mainly clay pebbles.

Does Hydroton (LECA) absorb water?

Yes, Hydroton absorbs and retains water, ensuring excellent aeration.


LECA balls can be of various types.

Some plants may not work well with these balls. So, you will need to choose the type carefully for the garden.

One more thing that you must keep in mind is the draining holes of new pots.

It would be best if you used closed-bottom containers while using LECA.

In closed-bottom containers, LECA can retain water, and plants can absorb water whenever necessary.


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