Matala Bio-Active Stone is a very unique filter media. It is a ceramic highly porous material with incredible internal surface area for bacterial growth. The Bio-Active Stone is star shape for a very good reason. The star shape allows for good even flow of water over the entire surface of the stone. Typically this type of media is used in a "Shower Tower" or "Trickle Filter". The media is stacked vertically inside a tall cylindrical tank or vessel. Pond water is sprayed to the top of the tank and splashes down aggressively over the filter stone. With very high flow rates splashing down, a super high oxygen content is provided to the outer and inner surfaces of the stone. The bacteria which will grow in this environment is super healthy and "Active".
This type of Shower Filter was made famous by the Japanese koi breeders who use it to maintain the ultimate water conditions for their valuable koi stocks. The filter is considered state of the art. It will accomplish multiple tasks.