Hydrofarm Geolite Pebbles | 45L - 8-20mm

Natural Clay Growing Medium for Root Ventilation, 45L

Growing media that compacts or holds too much water starves roots of oxygen, which shows up as slow growth or root rot long before it's obvious above the surface. Geolite Pebbles are made from 100% natural Italian clay, industrially fired at high temperature and treated to hold a consistent EC and neutral pH batch to batch.

This 45L bag of 8-20mm pebbles delivers high total porosity for root oxygenation and efficient drainage, working across drip feed, deep water culture, and flood-and-drain hydroponic, hydroculture, and aquaponic systems.

Key Features & Benefits

• 100% natural Italian clay — industrially fired at high temperature for a consistent, reusable growing medium.
• Consistent EC and neutral pH — treatment keeps batch-to-batch chemistry stable rather than introducing unpredictable swings.
• High total porosity — roughly 85% by volume, giving roots the oxygen access that dense media can't provide.
• Multi-system compatible — suited to drip feed, deep water culture, and flood-and-drain setups alike.

Who Should Use Hydrofarm Geolite Pebbles

Hydroponic, hydroculture, and aquaponic growers who want a stable, low-EC, neutral-pH clay medium for root support and drainage.

About Hydrofarm

Hydrofarm's growing-media catalog includes Geolite clay pebbles alongside rockwool, coco, and other substrates, supplying growers with materials for hydroponic and horticultural production.

Frequently Asked Questions

What are these pebbles made from?

They're 100% natural Italian clay, industrially fired at high temperature to produce a consistent, reusable growing medium. That firing process is what gives the pebbles their stable structure batch after batch.

What is the total porosity?

Approximately 85% by volume, which is what gives the medium its root-oxygenation and drainage properties. That much open space keeps oxygen reaching the root zone even in a saturated system.

What systems is this suited for?

This medium suits drip feed, deep water culture, and flood-and-drain systems. It works equally well across hydroponic, hydroculture, and aquaponic setups.

How do I prepare new clay pebbles before use?

Rinse the pebbles thoroughly before their first use to remove clay dust. Then check pH and EC in your system after adding them, since a large volume of fresh medium can briefly shift readings.