Rockwool, also known as stone wool, is a popular growing medium used in hydroponic and soilless gardening systems. Made from natural basalt rock, Rockwool provides an inert and sterile substrate for plant roots to grow in. Its high water retention and aeration properties make it an ideal medium for germination, seedling propagation, and hydroponic systems. With its versatility and ease of use, Rockwool is favored by growers for its ability to support healthy root development and optimize plant growth in various indoor gardening setups.