Grodan Gro Block Improved GR4 Small 3" No Hole 3" x 3" x 2.6" StripNew Grodan Improved! Improved product at current pricing. New density + new hydrophilic technology = better water distribution and root development. The uniform distribution of water and nutrients throughout the block allows for more efficient use of the entire substrate volume Full saturation of the blocks with no dry spots and improved EC control with less water is achieved in the rootzone due to the uniform, optimized wool resulting in a