Grodan IMPROVED Gro-Blocks 8"X8"X4" Uni-Block (GR40) filter Its porous nature allows it

Its porous nature allows it to suck up and hold onto moisture

Protect with the global leader in 2-way humidity control

Replace the catalytic carbon filter after 2

Made of UV-resistant

This combination of nutrients will lower pH over time while including the extra soluble calcium

Grodan IMPROVED Gro-Blocks 8"X8"X4" Uni-Block (GR40) filter Its porous nature allows itGrodan Stonewool (rockwool) is made from molten rock spun into cotton candy like fibers and then compressed into cubes, blocks, or slabs. Where other rockwool brand manufacturers cut all sizes from one batch of wool, Grodan is unique by making different types of fibers. The purpose is to support the requirement of the plant in the different plant stages. Grodan has a tremendous capacity for absorbing nutrient solution while retaining plenty of oxygen