Grodan Rockwool is a mineral wool made from molten basalt and limestone rock that is spun into cotton-candy like fibres and then compressed into cubes, blocks or slabs. Being made from natural rock, Grodan is a mineral based product used in hydroponic growing applications.
75mm Block with 42mm x 40mm hole
DM 4G 42/40 growing blocks are individually wrapped and are ideal for small plants and transplanting. These are often referred to as a 3" cube with large hole. The blocks feature grooves on the base to promote good drainage.
The blocks can be used for direct plant sowing or can receive rooted propagation cubes such as the AO 36/40 plugs directly into the DM 4G 42/40 hole. These blocks can also be placed on top of a Grodan Slab for larger growing volume.
Grodan Delta guarantees an optimum balance of air and water. The variation of small and large pores throughout the block ensures that the roots are always supplied with sufficient air and water.
DM 4G 42/40 blocks measure 3 x 3 x 2.5 inches (7.5 x 7.5 x 6cm approx.).