Grodan Gro-Blocks are clean, lightweight, and easy-to-use. Professional growers love Grodan Gro-Blocks because they allow efficient use of water and nutrients throughout the growth cycle. Effortless start-up of propagation. Grodan Gro-Blocks are perfect for propagating young plants under a wide range of propagating conditions. The Grodan Gro-Blocks are easy to saturate and water is distributed uniformly throughout the block, for reliable root development and plant growth Excellent root growth throughout the block.