Enhance your aquarium ecosystem with the Eheim SUBSTRATpro+ Oxygen. This newest biological filtration from Eheim, the Substratpro + Oxygen increases metabolic activity, improves water quality, and makes water more clear. Thanks to the innovative +O2 function, which intensifies the filtration process through activated super-oxygen (O2-), both filter bacteria and the entire ecosystem benefit from superior oxygen supply. Features high porosity of 45% for an above-average settlement area of filter bacteria, and is pH neutral. Suitable for fresh and sea water.