Expanded clay 3L

Expanded clay provides moisture regulation, root support and a breathable structure.

Expanded clay is a lightweight, expanded ceramic material that provides excellent support for plant roots, moisture regulation, and air circulation. Also known as hydro pebbles, these expanded clay pellets are perfect for a wide range of applications – from creating a drainage layer in terrariums to supporting root growth in hydroponics and propagation systems.

Thanks to their spherical shape and porous structure, expanded clay pebbles store water while allowing air to circulate freely through the substrate. This makes them one of the most versatile and reusable growing media for indoor gardening. Whether you're cultivating orchids, rooting cuttings, or regulating water flow in a closed environment, these durable pebbles help you maintain the perfect balance between moisture and oxygen.

At Sybotanica , we offer expanded clay in practical, resealable bags suitable for both small and large containers. Clean, inert, and ready to use straight from the bag.

Expanded clay in hydroponics and water-based cultivation

In hydroponics , the roots are held in or above water. To keep them upright and healthy, a hydroponic substrate is needed that supports the plant while allowing free water and air circulation. Expanded clay pebbles fulfill precisely this function. Their porous structure retains moisture for extended periods but dries quickly on the surface, preventing rot and fungal growth. This dual action makes them one of the safest substrates for water-based growing systems.

Why expanded clay works so well in hydroponics:

• Inert and pH-neutral substance, does not affect nutrient solutions
• Promotes excellent root support . Oxygen supply
• Easy to rinse and fully reusable
• They simultaneously retain moisture and air.
• They do not decompose over time

Although the spheres themselves contain no nutrients, they work perfectly in combination with a nutrient solution. Simply soak and fill the hydroponic container, then place the plant directly into the bed of spheres – the roots will do the rest.

Expanded clay as a drainage layer in terrariums

Terrariums need a balance: too little water and the plants dry out, too much and rot sets in. This is where expanded clay comes in. This drainage layer is placed on the bottom of your terrarium, absorbs excess water, and forms a barrier between the waterlogged soil and the plant roots.

Advantages of using it in terrariums:

• Creates a breathable base layer that separates standing water from the ground.
• Supports stable humidity without waterlogging.
• Reduces the risk of mold , rot, and anaerobic conditions.
• It maintains air pockets for the health of the microbes.
• Keeps your system clean, tidy and long-lasting

Because they are inorganic, expanded clay does not decompose and does not release odors – perfect for closed terrarium environments.

Expanded clay as a mulch layer

Aside from their use underground, expanded clay is also excellent as a decorative mulch . Spread on the surface of your pots, it improves water retention by reducing evaporation and insulating the root zone.

As a lightweight aggregate , expanded clay also keeps pests like fungus gnats away by minimizing exposed moist soil. And with their warm earth tone, they form an aesthetically pleasing, minimal mulch layer.

Clean, durable and infinitely versatile

Expanded clay is ideal for:

• Propagation of cuttings in water
• The cultivation of orchids and moisture-sensitive plants
• Creating a base in closed terrariums
• Support for semi-hydroponic systems
• Mix into soil to improve aeration and drainage.

Because it is a natural mineral product , these expanded clays compact. They do not decompose, nor do they alter soil chemistry. Their neutrality makes them compatible with every plant and every planting system.

Use of expanded clay:

• Drainage layer in the terrarium: Place 2–5 cm on the bottom before adding soil.
• Propagation station: Fill a glass container with water and expanded clay, insert the cutting.
• Hydroponic system: Use as a complete growth medium in net pots or containers.
• Mulch layer: Apply 1–2 cm to the soil to retain moisture and reduce drying out.

Expanded clay is easy to rinse and dries quickly, so you can reuse it again and again without it losing its function.