Make Nexus the automatic choice
Continuing our long standing reputation for innovation, the Nexus Automatic System now enables Nexus owners to benefit from a fully automated cleaning cycle on their multi award winning Nexus filtration systems. Physically turning ball valves and manually switching pumps on and off will now be a thing of the past thanks to the Nexus Automatic System. All of the key processes that form the cleaning cycle are now controlled automatically with this easy to install kit.
The Nexus 220 and 320 feature a re-designed Eazy filter which now utilises the all new K1 Micro Filter Media, in a static bed, to deliver improved levels of mechanical filtration. The Nexus filter systems also use the acclaimed K1 Media in the moving bed to deliver outstanding levels of biological filtration. Together this combination of filter media work to deliver crystal clear and healthy water. All Nexus filtration systems can be installed on pump fed or gravity fed setups depending on your pond configuration. The Nexus 220 is suitable for ponds up to 18,000 litres (4,000 gallons) while for larger ponds the Nexus 320 can be installed on ponds up to 34,000 litres (7,500 gallons).
Specifications
Dimensions
How the Nexus Works
Water from the pond enters the nexus via the inlet into the inner chamber hich works as a vortex allowing larger solids to settle out. Water then passes through the grills in the stainless steel “Eazy” filter, where the finer particles are removed at the mechanical stage of filtration, thanks to the static bed of our award winning K1 Micro® filter media.
The mechanically clean water then passes to the outside chamber of the nexus where the K1 Media moving bed is located for biological treatment prior to being returned to the pond. At this stage, biological breakdown occurs through different strains of bacteria and filter feeders living on the protected surface area of each piece of the K1 Media. These bacteria convert Ammonia and Nitrite into less harmful Nitrate. Water then passes through the exit grill into the outlet, returning back to the pond.
Installing the Nexus
The Nexus MUST be installed on a solid, level base, a minimum of 1.2 metres x 1 metre. Failure to do this will cause irreparable damage to the filter and will therefore invalidate your warranty.
GRAVITY-FED INSTALLATIONS
By this we mean that your pump is going to be used to return the filtered water to the pond and therefore your filter will be supplied by gravity via a larger diameter pipe. In this situation the water level in the filter will be at the same level as the pond.
PUMP-FED INSTALLATIONS
By this we mean that if your pump is going to be used to supply the water to the filter, and the filtered water then returns back into your pond via gravity, i.e. down a waterfall, or through a large diameter pipe, this is referred to as PUMP FED (i.e. the water is fed to the filter using a pump).
Improved Mechanical Filtration
The new design of the Eazy enables the Nexus to capture solids more effectively than before. K1 Micro is used inside the re-designed Eazy helping to deliver improved capture of fine particles, delivering unrivalled mechanical filtration.
Improved Flow
The new Eazy features an improved pattern of slots in the stainless steel body which makes the filter more efficient. Water can pass through the Eazy through all sides and from below, much more effectively than before. This feature combined with the use of K1 Micro makes for improved flow rates through the entire mechanical filter stage.
Dramatically Improved Clarity
The Nexus 320 and 220 filter systems use two types of filter media to deliver optimum levels of clarity in your pond. K1 Micro is used in the Eazy to improve mechanical filtration while the tried and tested K1 Media is used in the moving bed outer chamber, delivering the biological filtration.
Easy To Clean And Maintain
A key feature of all Nexus filtration systems is the sheer ease of maintenance. This still remains the case with the new Nexus 220 and 320 systems. The Eazy is simply cleaned by using a combination of the cleaning pipe, air valves and ball valves fitted to the Nexus, meaning you don’t need to get your hands dirty. The clear lid fitted to the Eazy also makes it easy to visual inspect the K1 Micro media.
Better Solids Handling
Inside the centre mechanical stage of the Nexus, there is a much larger area for solid waste to be captured and to settle. This area can then be cleaned even easier than before ensuring the filter does not clog up with unnecessary amounts of waste.
Removable Eazy
All Eazy filters used in the Nexus 320 / 220 series can be removed if needed with the K1 Micro in place. This added feature is ideal when undertaking further maintenance.
Flow Rates
One of the factors that can have a significant influence on the general parameters of our ponds is turn over rate. This is the time that it takes for the total volume of the pond to pass through the filter system once. We recommend that for ideal performance a turn over rate of every 2 to 3 hours is found to be best.
Overview of Nexus Automatic System
The Nexus Automatic System can be installed on Nexus 220 and 320 filters manufactured after 2006, whether on gravity-fed or pump-fed installations. The kit includes a control box which connects up to an automated waste valve, airpump control box and an automatic inlet slide plate (for gravity fed models only). Once installed and connected to your pond pump and mains power the system will carry out cleaning cycles at timed intervals or when pressing the manual clean button.
Cleaning Cycle
The Nexus Automatic System will control the cleaning cycle fully automatically. Cleaning is done on a timer, which is factory set to clean once every 3 days, however, this is easily adjustable to fit in with your pond requirements. The Nexus Automatic System will run a cleaning cycle which lasts approximately 10 minutes.
Gravity Fed Cleaning Cycle
- Adjustable timer kicks in to start a cleaning cycle.
- Control box automatically switches circulating pump off.
- The water level in the Nexus equalises.
- Inlet valve closes whilst at the same time air is diverted from the outer bio chamber to the EAZY to clean the media.
- After the media has been cleaned, the waste valve opens.
- EAZY is drained to waste and inlet valve opens for a final flush of the EAZY.
- The waste valve closes.
- Air is diverted back from the EAZY to the bio chamber.
- Circulating pump is switched back on.
- Nexus returns to filtration mode.
- Adjustable timer kicks in to start a cleaning cycle.
- Control box automatically switches circulating pump off.
- The water level in the Nexus equalises
- Air is diverted from the outer bio-chamber to the Eazy to clean the media.
- After the media inside the Eazy has been cleaned, the automated waste valve opens.
- Eazy is drained to waste.
- The automated waste valve closes.
- Air is diverted back from the Eazy to the biochamber.
- Circulating pump is switched back on.
- Nexus returns to filtration mode.removed if needed with the K1 Micro in place. This added feature is ideal when undertaking further maintenance.
Frequently Asked Questions
The water level in the outer chamber is much lower than in the inner chamber. Why?
- The pump could be too powerful, so the Nexus is being emptied before the pond refills it by gravity.
- There could be a blockage in the transfer port between the inner and chamber and the outer chamber. You need to back flush it. You can download the instructions to backflush here.
- The Eazy needs cleaning. Or the Eazy’s steel screen needs cleaning. Beware of sharp edges!
What size pump do I need?
Maximum recommended flow on the 220 is 10,000lph and the 320 is 13,000lph, however suggested flow rates are lower. Slower is better for fine removal and clearer water. Aim to turn over your pond volume every two to three hours. The Evolution Aqua Varipump range are adjustable, and consume less energy when you turn them down.
Can Nexus be gravity or pump-fed?
Yes, it can easily be adapted to either filtration method by simply swapping the supplied rubber boots.
How much media does Nexus have/need?
The Nexus 220 comes with 18 litres of K1 Micro in the Eazy (inner chamber,) and 50 litres of K1 in the outer chamber.
The Nexus 320 comes with 20 litres of K1 Micro in the Eazy (inner chamber,) and 100 litres of K1 in the outer chamber.
For older models, the 300 and 310 contained 40 litres of K1 in the Eazy, and 30 litres for the 200 and 210.
Don’t change the amount of media in the Eazy as this affects particle capture, and ease of cleaning. The amount of media in the outer chamber can be increased however by up to 150 litres in total in the 220 and 300 litres in the 320 models.
Only increase the amount of media in the outer chambers for heavy stocking and heavy feeding. Note that if the total volume of media is increased in a newly set up filter it will take longer to mature, as there is more surface area for bacteria to colonise and the biofilm will be more thinly spread.
K1 Media can be purchased from your Evolution Aqua dealer, code MEDIA25L for 25 litres, and code MEDIA50L for 50 litre bags.
Do I need an airpump for Nexus?
Yes, it powers the moving bed biological filter and is also vital to the cleaning process. You need an Evolution Aqua airpump 75 for a Nexus 220 and an airpump 95 for a Nexus 320. If you increase the amount of media in the outer chamber you may well need a more powerful airpump. The correct size airpump to enable K1 Media to move is detailed in the below:
50-75 litres airpump
75 75-100 litres airpump
95 100-150 litres airpump
130 150-300 litres airpump 150
What is Nexus Automatic?
The Automatic is a separate system which can be fitted to Nexus filters, to enable automatic cleaning. By combining timers and automatic valves, Nexus can be converted and set to clean itself, as little or as often as required. It can be set to clean at night or while you are on holiday, and once set it means total hands-off cleaning. The more your filter is cleaned, the more that waste is removed from the system before being broken down. That means a cleaner pond, cleaner filter and healthier water.
The Automatic System can be fitted to all Nexus models manufactured after 2006, and both gravity fed or pump fed models. It can be fitted by the user or a pond filter installer. The Automatic system still requires a Nexus, airpump and a water pump, along with a power supply. During cleaning the Nexus will expel dirty water to waste, so an auto top-up fitted to the pond (not supplied,) is advised if the filter is set to clean frequently.
How long is the standpipe for the return in a Nexus that is pump-fed?
The return pipe is 40.5cm long in the 220 and 46cm long in the 320. This is a length of 4" pressure pipe which is factory fitted during production to the return chamber of the Nexus and sets the level of the water in the Nexus. It is removed when using the Nexus in a gravity fed pond. This can be quite difficult to retro fit as the hole is quite tight, you may find it easier using 110mm soil pipe as this has a slightly smaller outer diameter.
How much water is in the Nexus?
Nexus 220
Total volume of water 510 litres / 112 UK gallons / 135 US gallons
Outer chamber 405 litres / 89 UK gallons / 107 US gallons
Inner chamber 105 litres / 23 UK gallons / 28 US gallons
Nexus 320
Total volume of water 840 litres / 185 UK gallons / 222 US gallons
Outer chamber 635 litres / 140 UK gallons / 168 US gallons
Inner chamber 205 litres / 45 UK gallons / 54 US gallons
Waste not draining to waste when valve is opened.
Remove the outside union on the waste ball valve, open the valve, if no water pours out the blockage is under the Nexus, carefully push a suitable stick (such as a cane) and release the blockage, you can also remove the Eazy and access the pipe from the 1.5" hole in the bottom of the Nexus inner chamber.
Nexus Automatic Manuel