Bio house ceramic media is 10X more effective than normal filtration by cultivating beneficial bacteria. It is heat treated at 1300 degrees Celsius for 60 hours that causes the ceramic to break its internal bonds leaving behind a extremely high amount of porous structure that has much greater surface to allow optimal amount of aerobic and anaerobic bacteria populations to colonize and thrive. Such conditions are crucial for the rapid breakdown of ammonia nitrites and nitrates to improve water quality. With the large amounts of tiny holes, mechanical filtration is also achieved. Large organic solids and decaying matter are degraded at a far greater speed than conventional media. Dimension approx. / ea tube: 6.5" L x 1.5" W. Includes: 24 pcs Large Square Ceramic Bacteria House Tubes. Please note: The media is very fragile. We will try our best to hand pack and ship each media, however, due to the nature of the product, we can not guarantee if there is any breakage during shipment. Even if it breaks, it does not influence the function of the product. The color of the item may vary slightly due to photography and your own computer.