: Since it is manufactured at extremely high temperatures (3,000°F), it contains no pests, diseases, or weed seeds.
: Smaller 1-inch cubes are ideal for smaller propagation trays or starting seeds that will be moved quickly to a larger medium. : ~$18.99. .N/A 72PCS 1.2 in. Rockwool Cubes with Net Cups Go to product viewer dialog for this item.
: Never squeeze your cubes when wet. This crushes the delicate internal structure, reducing the oxygen-holding capacity and hindering root growth.
: Rockwool has a naturally high pH (around 8.0) that can lock out nutrients. You must soak the cubes in slightly acidic water (pH 5.5 to 6.5) for at least an hour before use.
Buying rockwool cubes at Home Depot is a reliable way to source a sterile, high-performance medium for hydroponics or seed starting. These cubes, made from molten basalt rock spun into fibers, offer an ideal air-to-water ratio that promotes rapid root development.
