🪴 Expanded Clay — Hydroponic Substrate

Cultivalley Expanded Clay — Quick Overview

🪴 Ideal for Hydroponics: Provides oxygen-rich roots and constant moisture.

💧 Excellent Drainage: Prevents waterlogging and root rot.

⚖️ Lightweight & Stable: Perfect for large pots, balcony boxes, or green roofs.

🌱 Healthy Root Growth: Porous granules allow roots to spread freely.

♻️ Versatile Use: Acts as hydroponic substrate, drainage layer, or soil conditioner.

🛠️ Easy to Use: Rinse before use for optimal plant health.

Description
Reviews

Cultivalley Expanded Clay — Versatile Hydroponic Substrate

What is Expanded Clay and why choose Cultivalley?

Expanded clay, also known as clay granules, is a porous, lightweight material made from fired clay. A special high-temperature expansion process creates the characteristic spherical granules, offering excellent aeration and drainage. Cultivalley Expanded Clay stands for high quality and purity and is available in sizes 2–5 mm, 4–8 mm, and 8–16 mm — ideal as a hydroponic substrate, drainage layer, or soil conditioner.

Key Benefits of Expanded Clay

🌱 Optimal Aeration for roots — promotes healthy root growth.
💧 Excellent Drainage — prevents waterlogging and root rot.
⚖️ Lightweight — perfect for green roofs or large containers.
♻️ Neutral & Durable — chemically inert, does not decompose.
🪴 Versatile use as hydroponic substrate, drainage layer, or soil conditioner.

Applications — Where Expanded Clay excels

Expanded clay is a real all-rounder: Whether in hydroponics, as a drainage layer in pots, for green roofs, or in aquaponics systems — its porous structure always ensures an ideal root environment. Typical uses:

Hydroponics: Plants grow directly in the clay granules, roots receive oxygen and constant moisture.
Pot & Bed Planting: Layer at the bottom or mix into soil as a soil conditioner.
Green Roofs: Reduces weight and improves drainage and water retention.
Aquaponics: Serves as both growth medium and water filter.

Which granule size for which use?

Choosing the right size is crucial for stability and drainage:

🔹 2–5 mm — ideal for small houseplants, cuttings, and finer substrate.
🔸 4–8 mm — all-rounder for most potted plants and hydroponic setups.
🔷 8–16 mm — for large plants, tubs, and intensive drainage needs.

How to use Cultivalley Expanded Clay correctly

Before use, rinse expanded clay thoroughly under clear water until the runoff is clear. This removes dust and production residues — especially important for hydroponics and aquaponics to maintain water quality.

Quick hydroponics guide:

1. Add a clay granule drainage layer at the bottom of the pot.
2. Place the plant and fill around the roots with expanded clay.
3. Provide a special hydroponic nutrient solution and monitor water levels regularly (e.g., with a water level indicator).

Practical tip: Hydroponic pots with water level indicators make care much easier — see Leni's specialized pots. Leni Hydroponic Pot

Expanded Clay as Soil Conditioner — Benefits & Use

When mixed into soil, expanded clay acts as an effective soil loosener and improves heavy soil structure:

Improved drainage prevents waterlogging.
Less root rot due to better oxygen supply.
Lighter soil — ideal for balcony boxes or green roofs.

Recommendation: For potted plants, mix about 30% expanded clay into the soil to significantly improve structure.

Green Roofs & Large Projects with Expanded Clay

For green roofs, Cultivalley Expanded Clay provides a lightweight solution with good drainage and water retention. Easy handling and low weight make installation efficient — perfect for urban greening projects.

Preparation: Check roof sealing.
Drainage: Add a clay granule layer.
Planting layer: Mix substrate and expanded clay.
Plant selection: Choose drought-tolerant species.

Practical Tips & Care

🧼 Rinse: Rinse thoroughly before use until the water runs clear.
🔍 Check: In hydro systems, regularly monitor water quality and nutrient concentration.
⚠️ No unwashed granules directly in the system — may cause cloudiness or clogging.
🪴 Water Level Indicator: Useful for precise watering. Water Level Indicator

Available Package Sizes & Purchase Info

Cultivalley Expanded Clay is available in convenient packages: 5 L, 10 L, 25 L, and 50 L. Choose the right size for your project: from small pots to large green roof installations — there is a suitable option for every need.

Buy expanded clay online? In our shop, you can easily select by granule size and package.

Hydroponics Setup & Styling — Perfect Combination

For a beautiful appearance and easy care, combine expanded clay with matching outer pots. Stylish pots protect the system and complete the design — check out models like Corona, Flori Jardiniere, or Atlas.

Why choose Cultivalley Expanded Clay?

Expanded clay from Cultivalley offers quality, purity, and versatile applications — whether as hydroponic substrate, drainage, soil conditioner, or for green roofs. Robust, neutral, and easy to handle — the ideal clay granules for hobbyists and professionals alike.

Further Info & Inspiration

Want to learn how expanded clay is produced or explore additional applications? Read our detailed blog article. Expanded clay: why this substrate is so good and what else you can do with it

Item information	Value
Substrate type:	Peat-free Hydroponics
Content:	5L/kg 10L/kg 25L/kg 50L/kg

Product safety information

Manufacturer information:

Gärtnereibedarf Kortmann GmbH
Olfener Str. 112
Nordrhein-Westfalen
Lüdinghausen, Deutschland, 59348
https://www.cultivalley.de

Average item rating

All reviews:

How do reviews work?

Total entries: 4

Super
Super dieser Blauton unsere Blumen fühlen sich wieder wohl.

Silke D , 24.05.2022 Verified purchase Voucher received

Blähton
Alles super, gerne wieder.

Katja U , 13.01.2022 Verified purchase Voucher received

Blähton 2-5 mm
Tolles Produkt gerne wieder

Johann D , 08.07.2021 Verified purchase Voucher received

M.k.
Alles super...

Michael K , 26.11.2020 Verified purchase

Total entries: 4

Cultivalley expanded clay

Cultivalley Expanded Clay — Quick Overview