50 Liter expanded clay (clay balls), Grorox, Hydroton, etc.

Derived from natural clay and known by many names, providing optimal oxygenation and drainage, Grorox expanded clay is a lightweight and completely reusable substrate for hydroponic gardening and cultivation of food plants.

Tip from Dirk: I also like to use the expanded clay for my potted plants as a 2-5cm bottom layer. This prevents root rot caused by waterlogging.

Unlike rock wool, Grorox can be environmentally incorporated into garden soil for improved drainage after its last use. It can also be used as a filling material for rooftop gardening. We use Grorox in the CultiMate system, as well as in the grid pots of our GrowStream and HydroCloner.

Using Grorox Expanded Clay in hydroponic and aeroponic systems

Before the first use, Grorox expanded clay must be thoroughly rinsed with water to remove any impurities such as sand, dust, or other residues.
It is recommended to systematically check the pH value of expanded clay substrates: place a few clay balls in a glass of water with a pH value of 6.0, stir well, and measure. If the pH is 7.0 or higher, soak the expanded clay in a diluted phosphoric or nitric acid solution (or liquid or powdered pH-) overnight, and then rinse it well. If your Grorox substrate is pH-neutral, thorough washing and rinsing as described above is sufficient.
After use: for reuse, the expanded clay is usually only washed to remove organic residues completely and rinsed thoroughly. However, in case of insect or mold infestation, it may be necessary to soak the clay balls in a strongly acidic solution (or liquid or powdered pH- with a pH of 4) for disinfection. Then rinse thoroughly to completely remove the acid.

Grorox expanded clay is suitable for systems by Terra Aquatica and others

Package Contents

1x Grorox expanded clay 50L

Terra Aquatica (GHE)