Hydroton Grow Rocks are a special kiln-fired, lightweight aggregate that is super-heated and formed into pebbles 8-16mm in size. The ceramic shell and inner pore structure retains moisture and releases it back to your plants roots as needed. Grow rocks will not compact, insuring excellent aeration for the life of your plant. It is reusable and lasts indefinitely, making it a great value. Grow rocks are excellent in net pots for Ebb & Flow and Drip systems.

They come in two sizes:

• 10 liter (2.5 gallons)
• 50 liter (13 gallons)