Premium material: Our rockwool cubes are made of basaltock inorganic fiber and compressed into blocks through a proprietary process. It has soft and even texture with good water absorption and strong air permeability, making it an ideal substrate material for soilless cultivation. Easy to transplant: These hydroponic rockwool cubes help seeds establish root systems due to their high water absorption and oxygen retention. The 1 inch square rock wool blocks maintain their shape well for easy transplantation. Slotted design: The hydroponic net pots feature bottom holes for healthy root development and even drainage, allowing roots to grow naturally through the net cup. Easy to use: Cut rock wool pieces with scissors, soak briefly in nutrient solution for about 10 seconds, and adjust EC and pH values to the required range for seeds. The optimal pH for most plant seeds is about 5.5. Maintain appropriate moisture, light, and temperature. When roots grow beyond 1 inch, transplant them. Package includes: 72 pieces of 1 inch rockwool cubes, 50 pieces of 2 inch net cups, and 1 self-watering cotton wick cord for effective soilless cultivation.