ZENSUI is an aquarium company in Japan. Their main aquarium product is an aquarium chiller, but they also sell LED light, Protein Skimmer and other aquarium products. Now ZENSUI has just released their new filter media called Bacteria Hold.
ZENSUI insists that Bacteria Hold does not require frequent maintenance like cleaning the media since the media does not clog the water flow. Additionally, Bacteria Hold has other interesting points. Bactria Hold contains a special material in the media to make it positively charged, making it easier to attract negatively charged, beneficial bacteria.
The surface and inside of the media is very uneven, with a huge surface area, so many bacteria can live in there and process tons of water. The picture below is showing the media with bacteria film without cleaning long time.
The picture below is a scanning electron micrograph (SEM) picture of the media surface. Bacteria Hold is not like other filter media currently in the aquarium market because it does not have a series of pores, but instead it is pitted with individual pores. Because of this distinction in porosity, there are anaerobic areas in the media that are capable of supporting anaerobic bacteria for denitrification. 
The weight of Bacteria Hold is very light, weighing as little as a third of conventional bacteria media. 30L of the Bacteria Hold media weighs 4.5kg, but the normal media is somewhere around 30L/15kg. A 1L of the S size of Bacteria Hold costs around $13, 3L of the M size media is $24 and 50L of L size media is around $290.
