Nexus EAZY 220 Titanium Pond Filter – 4,800 Gallon Koi Pond Filter with Mechanical & Biological Filtration

An external air pump is required to operate the K+Media moving bed biological chamber. Without aeration, the K+Media in the outer chamber does not fluidize — it sits static on the bottom and provides dramatically reduced biological filtration. The air pump creates the continuous turbulence that keeps the media suspended, maximizing contact between water and the bacteria-colonized surface area of every K+Media piece.

Evolution Aqua's recommended air pump sizing based on K+Media volume:

• 50–75 litres of K+Media: Evolution Aqua Air Pump 75 (minimum for standard 50L supply)
• 75–100 litres: Air Pump 95
• 100–150 litres: Air Pump 130

If you add additional K+Media to increase biological capacity, you must also upgrade to the appropriate air pump for the new volume. Contact us at (765) 508-4352 to order the correct Evolution Aqua air pump alongside your filter.

The Nexus EAZY 220 Titanium is rated for ponds up to 18,000 litres / 4,800 US gallons / 4,000 Imperial gallons. This rating assumes a moderately stocked koi pond with standard feeding rates. For heavily stocked ponds or high feed rates, Evolution Aqua recommends adding additional K+Media (up to 150 litres maximum in the outer chamber, with the appropriate larger air pump) to increase biological capacity.

For turnover rate: aim to pass the full pond volume through the filter every 2–3 hours. The maximum flow rate is 10,000 lph (2,640 US GPH). Slower flow rates generally deliver better mechanical filtration efficiency from the EAZY.

The 220 Titanium uses two different Evolution Aqua filter media for different purposes:

• K1 Micro® — in the EAZY (inner chamber), static bed, 18 litres: A small-diameter mechanical and biological media with 1,400m² surface area per m³. In the EAZY it operates as a static bed — not moving — to mechanically capture fine particles, pollen, and fish waste that the vortex settlement did not remove. Do not add more K1 Micro to the EAZY; the 18L volume is optimized for the EAZY's cleaning cycle.
• K+Media — in the outer chamber, moving bed (MBBR), 50L supplied: An evolution of K1 Media with additional outer cells and fins that create protected "quiet zones" for Rotifers and Vorticella. These higher organisms provide additional biological filtration beyond what bacteria alone deliver. The outer chamber is aerated — the air pump keeps K+Media in constant motion. Expandable to 150L maximum.

K1 Micro = mechanical, static, fixed volume. K+Media = biological, moving, expandable. They are different products serving different functions in the same filter body.

Yes — both are supported, but the Nexus 220 Titanium ships configured for pump-fed installation.

• Pump-fed: Your circulation pump sits in the pond and pushes water into the Nexus inlet. Filtered water returns to the pond by gravity via the outlet. This is the factory default configuration — no modifications needed.
• Gravity-fed: Water flows from the pond by gravity into the Nexus inlet (often via a bottom drain). Your pump sits in the outlet/exit chamber and returns filtered water to the pond. Requires removing the outlet standpipe and making additional plumbing adjustments. Carefully read the gravity-fed installation instructions included with the unit.

Both configurations deliver full filter performance. Gravity-fed installations are common with bottom drain pond designs.

The EAZY cleaning process is one of the Nexus's defining advantages — it requires no manual handling of the media and no pond shutdown:

1. Insert the cleaning pipe into the centre of the EAZY. Water level in the inner chamber begins to rise.
2. Divert the air supply from the outer chamber to the EAZY by switching the air valves. This agitates the K1 Micro and suspends captured waste.
3. Open the 1.5" waste ball valve. Suspended waste discharges to drain.
4. Close the waste valve, redirect air to the outer chamber, remove the cleaning pipe.

Cleaning frequency depends on fish load and feeding rate. The clear EAZY lid allows visual inspection at any time — if the K1 Micro looks visibly loaded with waste, it's time to clean. Most users clean weekly under normal stocking conditions. The Nexus Automatic Cleaning System (sold separately) automates this entire process.

The Nexus EAZY 220 Titanium is supplied with factory-fitted mounting fixings and fittings already in place for the Evolution Aqua Nexus Automatic Cleaning System — a system that automates the ball valve operations and air-switching that make up the manual cleaning cycle. When you add the Automatic Cleaning System, you simply connect the actuators and controller to the existing fixings — no drilling, no retrofit fabrication.

The Automatic Cleaning System is sold separately. Contact us at (765) 508-4352 to add it to your order.

Standard Nexus 220+ filters require a separate external UV unit — typically a dedicated UV housing plumbed in-line with additional unions, T-pieces, and bypass valves. The Titanium integrates the UV directly into the exit chamber of the filter body, after all mechanical and biological stages. This positioning is optimal: UV light acts only on clean, particle-free water, maximizing penetration depth and kill efficiency. Particulate matter in raw pond water absorbs and scatters UV energy, greatly reducing performance in pre-filtration UV installations.

The "Titanium-Enhanced" designation refers to the UV lamp sleeve material. Titanium dioxide-coated UV sleeves provide a photocatalytic reaction that generates hydroxyl radicals in addition to standard UV exposure, enhancing overall clarification performance beyond UV wavelength alone.

Evolution Aqua's own Varipump range is an ideal match — controllable output lets you dial the flow rate to the filter's optimal 2,640 US GPH maximum without overpowering the EAZY mechanical stage. Slower flow rates through the EAZY produce finer mechanical filtration. The Varipump's variable output also lets you reduce flow during EAZY cleaning cycles.

Any quality external or submersible pond pump sized for 500–2,640 US GPH is compatible. Avoid exceeding the 10,000 lph / 2,640 GPH maximum flow — higher rates reduce EAZY efficiency. Call us to discuss pump sizing for your specific pond setup: (765) 508-4352.