Biofilter for LiBERTY (2 pcs.) The EHEIM Liberty BioBlock is a high-performance biological filter medium designed specifically for use with EHEIM Liberty hang-on filters. Its porous structure provides an optimal surface area for beneficial bacteria colonisation, helping to maintain stable water parameters and a healthy aquarium environment. Placed in the filter cartridge, the BioBlock supports efficient biological filtration by breaking down harmful substances such as ammonia and nitrite, ensuring crystal-clear and safe water for your fish and plants. Features & Benefits: Designed for Liberty filters - perfect fit for the EHEIM Liberty hang-on filter series Biological filtration - encourages colonisation of beneficial bacteria Improves water quality - supports natural breakdown of harmful substances Durable and long-lasting - maintains efficiency over time Easy to use - simply insert into the designated compartment in the filter