logo general hydroponics europe



High quality, renewable, re-usable, non-toxic substrate

Natural clay composition for excellent oxygenation and drainage.

Grorox® clay pebbles are a light and completely re-usable substrate for hydroponic gardening and food production. Unlike rockwool, Grorox® can be dug into garden soil as a drainage improver when no longer required without causing pollution. We use them in large volume systems like the Aquafarm®, and to support plants in net pot containers in our Aeroflo® and Rainforest® systems.


How to use Grorox®:

  • Before using Grorox® for the first time it is important to thoroughly rinse your pebbles with water to remove any sand and wash off any remaining dust and residues.
  • We recommend that you always check the pH level of clay substrates: Put some pebbles in a glass of water with pH adjusted to 6.0. Stir well, let it rest, then measure. If the level is high (7.0 or higher), soak the pebbles overnight in a solution of diluted phosphoric or nitric acid (or pH Down liquid or powder). Then rinse thoroughly before using. If your Grorox® are neutral, just wash thoroughly and rinse well as above.
  • After use: for re-use, it is generally sufficient just to wash off all organic debris and rinse well. But if needed, and in case of insect or mould infestation, disinfect the pebbles by soaking overnight in a strong acid solution (or pH Down - at 4.0), then rinse thoroughly to ensure the acid is washed away. 

Use Grorox® with:

Grorox® available in:

· 50 L bags.

Related products