WON Hollow Quartz Bio-Beads...
Quartz Bio-Beads not only have a large effective surface area (8-20 times that of other filter materials) and an extremely permeable structure, but also contain a variety of elements such as calcium oxide, sodium, potassium, magnesium, etc., which is an ideal environment for nitrifying bacteria (aerobic and anaerobic). Therefore, it can cultivate extra multitude units of beneficial bacteria.