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What is perlite?

Perlite is an amorphous volcanic glass with a relatively high water content. It’s usually formed by water mixing with obsidian. It is also packed with silica. It expands greatly when heated enough, growing from four to twenty times larger.

Why is it so white?

The expanded material is a brilliant white, due to the reflectivity of the trapped bubbles.

Expanded perlite

Why is it helpful to gardeners?

In horticulture it makes composts more open to air, while still having good water retention properties. It therefore helps to make a good medium for hydroponics. Add it to your soil to stimulate root growth, improve aeration, drainage and moisture retention.

Density levels

  • Unexpanded (“raw”) bulk density: 1100 kg/m³ (1.1 g/cm³)
  • Expanded bulk density: 30″“150 kg/m³

Perfect for hydrophonic systems

Have no soil? Perlite provides aeration and optimum moisture retention for superior plant growth. Studies show outstanding yields when it’s used in hydroponic systems. Rooting cuttings? Then dip them in perlite first.

Where else can it be used?

It can be used in:

  • greenhouses
  • landscaping
  • house plants


  • neutral pH
  • sterile and weed free
  • Lightweight so ideal for use in container growing
  • Can be used as a carrier for fertilizer, herbicides and pesticides and for pelletizing seed

Where to buy perlite

We sell different grades and quantities. Please take a look at our online shop section.


How to add it to your compost – video

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