Rockwool may be the single most favored growing media used by hydroponic growers today. Also known as Stonewool, rock wool offers a perfect air to moisture ratio that allows plants to grow at accelerated rates versus many other means of cultivation. Growers use rockwool in conjunction with flood and drain or drain to waste tables that utilize precision drip irrigation systems to feed the plants. Grodan and Pargro are the industry leaders by a large margin, Grodan being the premium line and Pargro being the less expensive "value" line. Both offer fantastic properties that promote robust and healthy plant growth. Ebb and flow hydroponics systems along with flood and drain recirculating or drain to waste systems are popular among growers growing a variety of crops.