Sera Siporax Mini professional 270 g

A biological filter medium for small aquariums, 1,000 ml (270 g). This is the largest pack in the range; the others are 35 g and 500 ml (130 g).

What is different about siporax: it is not fired clay like ordinary filter rings but sintered glass. The material has a three-dimensional pore structure that maximises the surface area, and the fine pores are a suitable place for bacteria to settle.

Why the structure has to be interconnected: the pore network is connected throughout, so water rinses the bacteria continuously. In closed pores a bacterium would sit without flow and break down nothing. The same structure makes the medium self-cleaning, which extends the service interval of the filter.

What it does: ammonium, nitrite and nitrate are broken down by bacteria. In nature the surface of the bottom is enough for this, because little waste is produced per volume of water; an aquarium packs the same biotope into a small space, so the settling area has to be increased.

Why mini: siporax mini Professional was developed for small tanks, up to about 100 litres. It maximises the settling surface for bacteria while staying compact in shape, so biological filtration works even in a small filter unit. According to the manufacturer this pack is sufficient for 200 litres.