Description
Clay pebbles also known as LECA (Lightweight Expanded Clay Aggregate), Hydrotons, or expanded clay are lightweight, porous, semi-rounded pellets made from 100% natural clay. These are thermally expanded at high temperatures (appx. 1200°C), which causes the clay to “pop” like popcorn, forming a structure full of micro and macro-pores.
Expanded clay pebbles or LECA resemble oddly shaped, semi-rounded pieces of clay-colored popcorn. The high-heat popping during the manufacturing process gives the medium its large, airy macro-pores (spaces between each piece of expanded clay), in addition to its micro-pores, which are contained within each piece of expanded clay.
Horticultural clay pebbles are clean, pH stable, and offer great aeration and drainage in hydroponics, especially in flood and drain, deep water culture, and drip feed systems. Due to their unique structure and ability to cover a large surface area, they offer the ideal environment to foster beneficial bacterial growth around the root zone, leading to naturally healthier plants.
Drain freely and do not hold any excess water, providing good oxygen levels around the root; suitable for flood and drain systems, multi-pot and drip feed systems.
1–4 mm – Small Grade Clayballs
Appearance : Fine, small-sized round particles resembling gravel.
Best Uses:
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- Seed starting trays : Perfect for germination media.
- Microgreens & baby leafy greens : Ensures uniform moisture and aeration.
- EBB & Flow : As hydroponics / aquaponics media.
- Top dressing in potted plants : Prevents soil splash and fungal gnats.
- Biofilter media in aquaponics : Large surface area for microbial colonies.
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Advantages :
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- High surface area to volume ratio for beneficial bacteria.
- Retains moisture without clogging.
- Settles and fills netpot base tightly for small plant stabilizing.
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Netpot Compatibility: Small Grade Clayballs are not recommended with netted pot.
8–15 mm – Regular Grade Clayballs
Appearance : Medium-sized, semi-rounded pebbles.
Best Uses:
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- General hydroponic systems : DWC, flood & drain, drip systems.
- Kratky method : Keeps base stable while allowing air gaps.
- Aquaponics grow beds : Excellent drainage and bacteria habitat.
- Indoor decorative planters : Combines aesthetics with utility.
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Advantages:
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- Balanced water retention and air space.
- Provides anchorage for most hydroponic vegetables.
- Doesn’t compress or decompose over time.
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Netpot Compatibility:
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- 2-inch netpots – Usable, Suitable as a top covering or bottom filling.
- 3-inch netpots – Perfect fit.
- 5-inch netpots – Suitable as a mid-layer or with mix.
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15–30 mm – Big Grade Clayballs
Appearance : Large, lightweight, hollow-core balls with porous texture.
Best Uses:
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- Heavy plants : Tomatoes, cucumbers, bell peppers needing more base support.
- Dutch bucket systems : Enhances drainage and structural hold.
- Aeration layer in large pots and containers.
- Aquascaping or aquarium base media : Visually appealing and highly porous.
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Advantages:
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- High oxygen exchange.
- Structural support for larger plants.
- Doesn’t compact or block airflow in root zone.
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Netpot Compatibility:
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- 2-inch netpots – Too large; poor anchorage.
- 3-inch netpots – Feasible only if mixed with smaller sizes.
- 5-inch netpots – Ideal for base fill and plant stability.
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Note : These clayballs are designed to float when dry, though they may partially sink or become neutrally buoyant after prolonged soaking, especially the small ones, but they will still not sink completely like dense stones.