Cultiwool Rockwool Cube 7.5 x 7.5 x 6.5 cm

Cross grooves improve water flow under the block, and the black/white film prevents algae growth.

Drainage grooves

Cultiwool substrate blocks have drainage grooves on the bottom to improve water flow under the block. This is especially useful when the blocks are placed on growing tables and concrete floors. Another advantage of blocks with drainage grooves is that they limit the contact surface with the ground. This prevents diseases from spreading to plants through weak roots, often combined with excessively high temperatures.