Grodan Gro-Block Improved GR5.6 Large (3x3x4) w/Hole HRG It’s a measure of the

It’s a measure of the difference between vapor pressure in the leaves of your plants and the air surrounding them

FDA approved

The 78-cell side is for 1

Do not rinse

and other industrial related uses

Grodan Gro-Block Improved GR5.6 Large (3x3x4) w/Hole HRG It’s a measure of theGrodan Improved GR5. 6 Large 3"x3"x4" Gro Blocks optimized wool structure allows for faster rooting in and nutrient solution replenishment. New and improved wetting agent and hydrophilic technology greatly enhances the water characteristics giving even better water distribution over the height of the block. This results in greater plant development and steerability and more efficient use of water and nutrients. All while the Gro Block Improved