Evolution Aqua Nexus 220+Evolution Aqua Nexus 220+ Pond Filter Advanced Filtration for Clearer, Healthier Ponds The Nexus 220+ from Evolution Aqua is the next generation in pond filtration, combining mechanical and biological processes in one powerful and easy to maintain system. Building on years of proven Nexus technology, the 220+ model is enhanced with K+Media, an advanced filtration media that ensures faster bacterial colonisation, improved water quality, and long term