The manufacturer informs:

CHARACTERISTICS:

High-quality filter material in the form of porous ceramic tubes whose structure ensures good water flow and thus an adequate supply of oxygen and nutrients to the biological filter. The effective surface area of Pore Ring M is 500 m2/l, due to the complex pore system through which water can flow freely, supplying oxygen and nutrients to the nitrifying bacteria. The porous structure provides an excellent substrate for the colonisation of these bacteria, which transform ammonium ions (NH4+) and nitrites (NO2-) (both dangerous to fish) into relatively harmless nitrates (NO3-).

Measurements: 16x15mm