Expanded vermiculite is available in two particle sizes: fine (1–3 mm) and medium (3–6 mm), both in 100 L bags. It is a heat-expanded mineral that adds water retention and cation exchange capacity (CEC) to the growing medium — the opposite of perlite, which adds aeration. The difference between particle sizes does not change the chemical properties, only the particle size and therefore the crop or system where it is used.
Comparison | Expanded vermiculite: how to choose the right variant
