Eheim SUBSTRATpro is Eheim\u2019s premium biological filter media, designed to provide highly efficient biological filtration for aquariums.\nMade from pearl-shaped, highly porous sintered glass, SUBSTRATpro provides a large surface area for beneficial bacteria to colonise. These bacteria help break down harmful waste, reduce peak nitrite loads and support clear, healthy aquarium water.\nThe pearl shape allows water to flow more easily through the media, helping to reduce dead spots and improve overall filtration efficiency. With a surface area of approximately 450m\u00B2 per litre, this 1 litre pack offers excellent conditions for beneficial filter bacteria to thrive.\nThis 1L / 720g pack is suitable for use in external canister filters, sump filters, Eheim Aquaball filters and Eheim Biopower filters. SUBSTRATpro should be placed after mechanical filter media and can be used in one or more layers depending on your filter setup.\nProduct Features:\n--Genuine Eheim SUBSTRATpro biologi.