Hydroponic Grow Pebbles – Calcined Diatomaceous Earth 6mm-12mm

Give plant roots a highly porous growing environment with our Hydroponic Grow Pebbles, made from 6–12mm calcined diatomaceous earth.

Diatomaceous earth, also known as diatomite, is a naturally occurring, silica-rich material formed from the fossilised remains of microscopic aquatic organisms called diatoms. Its naturally porous structure gives it a high capacity to absorb and hold water.

Our diatomaceous earth is calcined (heat treated) to produce stable 6-12mm granules suitable for use as a hydroponic growing medium.

The result is a versatile alternative to conventional hydroponic growing media, combining moisture retention with an open granular structure.

Why Choose Diatomaceous Earth Grow Pebbles?

Highly Porous

Diatomaceous earth contains an extensive network of microscopic pores, giving the material excellent absorption properties.

Retains Moisture

The porous granules absorb and retain water, helping the growing medium hold moisture around the root zone.

Promotes Aeration

The coarse 6–12mm granules create spaces between the pebbles, helping maintain an open growing medium with air space around the roots.

Free Draining

Spaces between the individual pebbles allow excess water and nutrient solution to move through the growing medium.

Stable Granular Structure

Calcination produces a stable granular material suitable for use in growing media.

Naturally Silica Rich

Diatomaceous earth consists predominantly of silica and has a naturally porous structure.

How Do Hydroponic Grow Pebbles Work?

Their effectiveness comes from two different types of space within the growing medium.

Between the pebbles, the 6-12mm granules create larger spaces through which water can drain and air can circulate.

Inside the pebbles, microscopic pores absorb and retain water.

This combination makes calcined diatomaceous earth particularly useful when you want a porous hydroponic growing medium that provides both drainage and moisture retention.

Please note : the 1L will come in a pouch instead of a tub.

How to Use Hydroponic Grow Pebbles

1. Rinse before use

Rinse the pebbles thoroughly with clean water before first use to remove loose particles and dust.

2. Add to your growing system

Use as a hydroponic growing medium or to support plants in suitable net pots and growing containers.

3. Add your plant

Position the plant carefully and add the pebbles around the roots to provide physical support while maintaining an open root zone.

4. Manage your nutrient solution

Water and feed according to the requirements of your plants and hydroponic system. Regularly monitor nutrient concentration and pH as appropriate for the crop being