The material is same as old tipe but new one has Hole at center of the Bacteria House that make more Surface area!

Moreover, since a large number a big hole, water permeates to an inside and raises sufficient filtration effect.

Adhesion of bacteria appears clearly in about about three weeks after installation of a bacteria house, and an effect shows up.
In the hole of the size of a bacteria house, and a static electricity-action, floating matter is caught effectively and they are decomposed promptly. The transparency of water rises in a bacteria house.