Grodan Grow Chunks, 2 Cubic Foot Bag, Case of 3. Grodan Stonewall Grow Chunks are perfect for your hydroponic systems. These light, airy & versatile. GrowChunks are about 3/4 inch square each and can be used in pots around blocks or alone. You also have the ability to layer this product with other media, such as layering with coco fiber, clay pellets or soil for added aeration and increased moisture holding properties. Great for hydro systems or container gardening.