03/06/2026
THE NEXUS DEBATE
The Evolution Aqua Nexus 220 and Nexus 320 have been a mainstay of the koi industry for many years, and there is a reason why so many are still in operation today.
Before comparing them to drum filters, it's worth remembering that they are different types of filtration systems. A Nexus combines mechanical and biological filtration within a single unit, whereas a drum filter is a mechanical filter that is typically used alongside a separate biological stage.
The strength of the Nexus has always been its simplicity and biological performance. When correctly sized for the pond, properly maintained, and allowed to mature, it provides an excellent environment for beneficial bacteria to convert ammonia and nitrite into less harmful compounds.
Another reason for its continued popularity is reliability. With a relatively simple design and no automated cleaning mechanisms, many Nexus filters have remained in service for well over a decade with routine maintenance and replacement of wear-and-tear items where required.
Filtration technology has moved on over the years, and there are now systems available that provide more efficient mechanical waste removal. However, the Nexus remains a well-established and widely used filtration system that continues to deliver good results on many koi ponds.
The fact that so many Nexus 220 and 320 filters are still running successfully today speaks for itself.
What's your view? Would you still choose a Nexus, or would you go in a different direction with a modern pond build?
