6 Cups | Inert Expanded Clay Media for Self-Watering, Semi-Hydro & Aquarium Planters

Engineered for growers who want a cleaner, more inert growing medium, this 6-cup bag of Mossari LECA gives roots the airflow and structure they need while still allowing moisture to wick upward from the reservoir below.

Unlike traditional soil blends, LECA is made of lightweight expanded clay pebbles that help maintain open air space around the roots. The result is a highly aerated root zone with a simple, low-mess setup that works beautifully in self-watering planters, semi-hydro systems, orchid pots, aquarium-mounted planters, and Mossari’s in-tank planter baskets.

Built for Airflow and Wicking

Self-watering systems need the right balance of moisture access and oxygen around the roots. Traditional potting soils can stay too wet, compact over time, or break down in constant-moisture environments.

LECA creates open structure throughout the planter, helping water move upward while maintaining strong airflow around the root zone. That makes it a strong option for growers who want a stable, inert medium with no added fertilizers or organic amendments.

Why Choose LECA

LECA is the stripped-back option for growers who want more control.

Best for:

• Semi-hydro houseplants
• Orchids and other airflow-loving roots
• Aquarium-mounted wicking planters
• In-tank planter baskets for plants rooting directly into aquarium water
• Growers who prefer fertilizer-free media
• Anyone testing a cleaner alternative to organic substrate

Because it contains no added nutrients, the plant gets moisture from the reservoir and nutrition from whatever water or nutrient source you provide.

Aquarium-Compatible

LECA works especially well across Mossari’s aquarium lineup.

In Mossari aquarium-mounted wicking planters, water moves upward through capillary action rather than flowing downward through soil. LECA gives roots access to that moisture while keeping the planting zone open and breathable.

It also works beautifully in the In-Tank Aquarium Plant Holder and Propagator, which is already designed for lightweight media like LECA and similar substrates. That product is specifically positioned for roots to grow directly into the tank water below, making LECA a clean, low-mess option for riparium-style setups and nutrient-absorbing greenery above the aquarium.

How Much Does 6 Cups Fill?

One 6-cup bag roughly fills:

• One Large Aquarium-Mounted Wicking Pot
• One Large Wicking Pot - Self-Watering Planter
• One Oasis Planter
• Two Small Aquarium-Mounted Wicking Pots
• Two Soma Planters
• Four In-Tank Aquarium Plant Holder and Propagator baskets

Because LECA is chunky, exact fit can vary slightly depending on pebble size and how tightly it settles.

Prefer a Nutrient-Amended Mix?

If you want a substrate with added root-zone nutrition, see the Mossari Enriched Blend Substrate.

If you want a more traditional wicking mix with organic structure but no added amendments, see the Mossari Inert Wicking Substrate. Your current collection is already segmented that way, so LECA fits well as the cleanest and most inert option in the lineup.

Ingredients

• 100% lightweight expanded clay aggregate
• No added fertilizers. No organic amendments.