DaPlug Sponge Cubes - Case of 2,100Description DaPlug Sponge Cubes: These all natural, eco friendly sponge cubes are an ideal solution for seed starting. Perfect for use in both soil and hydroponic applications, they offer a highly spongy texture, which provides an excellent ability to retain moisture. This results in an optimal air to water ratio. Additionally, their ability to dry evenly also promotes root development, making these sponge cubes suitable for both seeds and clones.