Evolution Aqua Nexus Eazy 200 Manual

Manufactured by Evolution Aqua Ltd.
Evolution House
Kellett Close
Wigan WN5 0LP
Tel: [phone]
Fax: [phone]
Web: www.evolutionaqua.com
E-mail: [email protected]
Installation & Operating
Instructions
Note: Do not attempt to operate this unit
before reading the manual thoroughly
200
200/300

Nexus Eazy Specifications and Flow Rates
Follow your relevant section carefully and your filter
will perform correctly providing a perfect environment
for your Koi. One of the factors that can have a sig-
nificant 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. On Nexus ponds a turn over of every 2
to 3 hours is found to be best.
Nexus Eazy 200
Max flow rate: 10,000 litres/hr 2,200 UK or
2,640 US gallons/hr
Max pond size: 18,000 litres 4,000 UK or
4,800 US gallons
Kaldnes K1: 50 litres (for bio stage – max
150 litres possible)
30 litres (for Eazy – max 30
litres possible)
Thank you for purchasing your Nexus Eazy™ filter.
We are sure you will be delighted with its perform-
ance. You should have already decided whether
your filter system will be pump or gravity fed. Please
go to the relevant section and read
thoroughly before installation.
The Nexus Eazy filtration unit has been designed
on the principles of minimum maintenance, high
performance and a compact foot print. This design
delivers optimum water quality by using the Kaldnes
Moving Bed ™ process.
Basic Operation Nexus:
This section briefly explains the basic operation of the
Nexus filtration system. Water is delivered to the inlet
of the filter and enters chamber A (see fig. 15). This
chamber is the main mechanical stage of the filter.
All of the solids and debris are
stopped in chamber A and are
sumped to waste via a 1.5 inch
ball valve provided. The water
then passes to chamber B con-
taining the kaldnes Moving Bed
where the biological filtration takes
place. The air ring at the base of
chamber B constantly agitates
the media. Chambers C & D are
empty and allow the clean water
to return to the pond.
Basic Operation Eazy :
The Eazy™ is a stainless steel ves-
sel containing a volume of static
K1 media which is located within
the centre chamber of the Nexus.
Water enters the centre chamber
and then enters the ‘Eazy’ via slots
in the lower half of the unit. This
results in a downward flow causing
many of the larger solids to settle
out prior to entering the Eazy. The
size of the slots will not allow large
mechanical waste to enter the
cylinder thus acting as a first stage
mechanical filtration. The water
then passes through the static K1
media, utilising up and side flow
and this process causes the fine
solids to become entrapped. The
mechanically clean water then
passes to the outside chamber of
the Nexus where the Kaldnes mov-
ing bed™ is located for biological
treatment, prior to being returned
to the pond.
Nexus Eazy Rev. 1.04 page 2
789.6
60
324.7
5
417.7
464.9
max water level
59.7
324.7
5
742
840
634.3
189
425
692 D
766.5
1116.3
531.9
1250

Nexus Eazy 300
Max flow rate: 15,000 litres/hr 3,300 UK or
3,900 US gallons/hr
Max pond size: 34,000 litres 7,500 UK or
9,000 US gallons
Kaldnes K1: 100 litres (for bio stage – max
200 litres possible)
45 litres (for Eazy – max 45 litres
possible)
On opening your Nexus you will find the
following;
Fig.1 Nexus 200 or 300 main body
Fig.2 Stainless steel Eazy vessel, comes fitted
Fig.3 Stainless steel centre pipe, comes fitted
Fig.4 Kaldnes K1 30 litres, for the Eazy 200, 45 litres
for the Eazy 300
Fig.5 Nexus isolation pipe, used during cleaning.
Nexus Eazy Rev. 1.04 page 3
1323
OUTLET
INLET
757
1434
1131 D
51
445
605
52.5
516
619
725
868
655
52.2°
WATERLEVEL
OUTLET: NOMINAL PIPE
BORE 100mm
INLET: NOMINAL PIPE
100mm
Fig. 2 Fig. 3
Fig. 1
Fig. 4 Fig. 5
Fig. 6 Fig. 7
Fig. 11
Fig. 10
Fig. 9Fig. 8

Installation Section Pump + Gravity Fed
We recommend that you read all the following sec-
tions, then select the appropriate installation sec-
tion.
• Preparation
• Installation Equipment
• Pump Fed installation Section
Preparation
A base level solid ground is required. It should be
a minimum of 1.2m x 1.0m, to allow easy access to
valves and for maintenance purposes.
Important:
The Nexus filter needs to be equally supported on
the three pairs of feet which are located under the
vessel. This is to prevent possible distortion when it is
full of water.
The best op-
tion for this
would be a
level 100 mm
thick concrete
plinth. Al-
though deck-
ing, paving
slabs or gravel
would be suf-
ficient as long
as the Nexus sits level and is not allowed to deflect
under the weight of the water.
Installation Equipment required or recommended:
1. Pond Pump, with a maximum actual flow rate
of no more than your Nexus model allows (see
pages 2 or 3 for specs).
2. Air Pump to power the kaldnes K1 Moving
Bed, see specifications for size of pump
required on page 6.
3. Length of hose or braided pipe (10 mm in
ner diameter) to connect the air pump to the
already positioned/supplied air ring.
Fig.6 Kaldnes K1 for bio chamber Nexus 200 = 50
litres Nexus 300 = 100 litres.
Fig.7 Inlet plate (Gravity fed only).
Fig.8 Weir plate, comes fitted (Nexus 200
pump fed only).
Fig.9 Standpipe (Nexus 300 pump fed only).
Fig.10 1.5 inch ball valve, for pressure inlet pump
fed only.
Fig.11 Two rubber connecting adapters, fitted
Pump Fed Systems
The nexus filtration system can be used in two ways
pump or gravity fed (fig.12 –pump fed)
Important: you must raise your pump off the pond
floor. It is incorrect practice to place a pond pump
on the base of any pond as failure in the filtera-
tion system. Pipe work or connectors could lead to
complete drainage of the pond. Therefore leave a
sufficient gap
( min. 12”) for
your Koi
Gravity Fed
Systems
In fig 13 you can
see a typical
set-up of a grav-
ity system.
WATER
Isolation
Valve (y)
Return to Pond
Alternative
Return to Pond
Via Waterfall
Pond
Reducer
PurgeValve
(x)
Pump
LEVEL
Isolation
Valve
Pond
Reducer
Return to
Pond Reducer
(If Required) (If Required)
Pump
Raised off
Bottom
Min 12”

Nexus Eazy Rev. 1.04 page 4
Fig. 12
Fig. 13

On the 300, the level is maintained with the exit
standpipe in the outlet (Fig.16). An overflow grill
is cut out of the central chamber wall for added
protection(Fig.17). In the 200, a weir plate (Fig.18)
sets the Nexus water level and the overflow is built
into the wall between the two chambers, with a
section moulded at a lower height (Fig.19).
NB. NON UK CUSTOMERS PLEASE NOTE: if you are
pump fed, you will receive the weir (200) and stand-
pipe (300) loose and they need to be inserted as
shown. The weir is simply dropped ito place. To
insert the pipe, the top two bolts and locknuts are
removed from the stainless steel outlet plate. Gently
pull the plate forward and firmly push the standpipe
in place. Replace the nuts and washer. IF THIS PIPE
IS NOT FITTED, THE WATER LEVEL IN THE BIOLOGICAL
CHAMBER WILL BE TOO LOW FOR THE FULL USE OF
THE BIO MEDIA AND THE EAZY !
The unit can be any height above the surface water
level, allowing adequate gravity return to the pond
( subject to the maximum performance of your cho-
sen pump) However, care needs to be taken that
the top of the Nexus is at least 500 mm higher than
the discharge point of the gravity return pipe into
the pond ( assuming that the gravity return pipe dis-
charges above the surface of the pond. If the grav-
ity return pipe discharges below the surface of the
pond. Please allow 50 mm from the exit of the Nexus
to the surface of the pond).
The length of this depends on the distance
between the air pump and the Nexus,
4. Ensure that the air pump is sited well above
water level to prevent water siphoning back
from the filter into the pump due to power cuts
or maintenance shut downs.
5. Pipe work from the unit’s waste valves to the
intended discharge point. This can be rigid
pipe work to a simple flexible hose.
6. A PVC reducer to connect your circulating
pump or pipe to the rubber connector sup
plied with your Nexus ( the size of which will
depend on your choice of pipe work to and
from the pond itself)
7. Care must be taken
when connecting
the waste valves (fig.
14 for the suggested
method) to your
chosen point of dis
charge valve.
Pump Fed Installation Section 200 + 300
Important: Essential First Action
In any pump fed installation, the first step is to make
sure that the water level weir plate/standpipe is in
place (Fig. 15 or Fig.16).
THIS MUST BE DONE BEFORE ANY ADDITIONAL INSTAL-
LATION WORK IS CARRIED OUT.
Figure 12 illustrates a typical pump fed installation.
When selecting the position of your Nexus Eazy filter,
carefully consider the following factors:
Nexus Eazy Rev. 1.04 page 5
Fig. 14
Chamber A
Max. Water level
adjustable standpipe
(pump fed)
Safety overflow
Exit plate
Chamber B
Chamber C
Chamber D
Chamber A
Max. Water level
Safety overflow
Exit plate
Chamber B
Chamber C
Chamber D
Fig. 15
Fig. 16 Fig. 17
Fig. 18 Fig. 19
Fig. 20 gravity version

The gravity return pipe work from the exit point of
the Nexus to the pond needs to be a minimum of
75 mm (external diameter) and should have no
restrictions. Great care should be taken to ensure
that no air locks are created within the gravity re-
turn pipe work. The pipe work from the pond pump
to the inlet of the Nexus will need to be connected
to the rubber 50 mm connecting adapter that is fit-
ted to the inlet of the Nexus. A PVC reducer may
be required, the size of which depends on the size
of the pipe you have chosen to connect the pump
to the Nexus. The 75 mm (minimum) gravity return
pipe work will need to be connected to the rubber
adapter on the exit point of the Nexus. This pipe is
then extended / returned to the pond or waterfall
as required.
Gravity Fed Installation Section 200 + 300
Once you have positioned the Nexus, please
connect the pipe work in accordance with your
requirements.
Recommendations:
The rubber 110 mm / 4 " boot supplied will go onto
the inlet point, connecting the Nexus to the pond
after the recommended isolating valve has been
fitted between the bottom drain and your Nexus.
The other rubber boot (supplied) will then fit onto
the outlet side of the Nexus to connect the outlet
to your circulating pump. A PVC adapter / reducer
may be required.
Air Pump Installation Pump + Gravity
Now that you have your Nexus installed, we need to
get the Kaldnes installed and the airpump attached
to circulate it. This will be circulated permanently in
the outer biological chamber when your system is
running and for cleaning only in the central cham-
ber when maintaining the Eazy (Fig.21). Your choice
of air pump will depend on how much Kaldnes you
have in your biological chamber…see table. The
size of air pump required will depend on the amount
of K1 media used.
Air Pump Size Capacity of K1 media
15/20 litres per min 50 litres of K1 media.
40 litres per min 100 litres of K1 media.
80 litres per min 100-150 litres of K1 media.
The air pump is connected using a
pipe (10 mm inner diameter) to the
air ring inlet which is positioned on
the outside of the Nexus). It is
recommended to position the air
pump higher than the surface water
level in the Nexus to prevent water
flowing back into the air pump when
it is switched off (see fig. 22).
Getting Started
Empty your correct amount of K1 into the empty
outer biological stage. Fill your Eazy with its appro-
priate amount (Fig.4). Once the nexus is plumbed
in, the pump is fitted and the media is in, it is ready
to be started. As with anything, maintenance is an
individual and personal thing. Cleaning and main-
taining the Nexus will depend on flow rate, feed,
stocking, blankert weed etc. A summer pond after
a blanket weed treatment will obviously need more
care than a December unheated pond with no
food fed. Be aware that any movement of the Eazy
K1 will disturb fines back into the pond. The biome-
dia k1 is zero maintenance. The cleaning regimes for
both pump and gravity installations are listed below.
When all the connections have been made the Nexus
filter may be filled from the pond and the air pump
switched on. The K1 media will not attain neutral
buoyancy completely to begin with. Most of the
media floats, which is normal. In existing mature pond
water the media may start to circulate fully in as lit-
tle as 2 - 3 hours. In a newly filled and stocked pond
this full movement may take up to a week to occur.
Either way a constant and even circulation should be
achieved throughout the chamber. (For more
information about this please read the Kaldnes K1
media section).
System running and maintenance :
To achieve optimum water clarity we recommend
that the “Eazy” be air backwashed and purged on a
regular basis. The frequency of cleaning will depend
on the loading of the pond. The longer the filter is left
undisturbed the finer the filtration will become. How-
ever the filter must be purged regularly to avoid circu-
lation pump starvation on a gravity system or chamber
overflow on a pump fed system.
Cleaning Gravity Procedure
1 Stop the circulation pump.
2 Wait a short a period of time so as to allow the
water levels within the Nexus to stabilise.
Nexus Eazy Rev. 1.04 page 6
Fig. 22
Fig. 21

8 Remove the Isolation pipe
9 Close the airvalve.
10 Open inlet valve.
11 Restart the pond pump.
Kaldnes Moving Bed™ Process
Kaldnes Moving Bed™ process, has been scientifically
tried and tested in fish farming and waste treatment for
over 10 years.
Developed by Professor Halvard Ødergard at Trondheim
University of Science and Technology the Kaldnes
Moving Bed™ bio film process has been designed
specifically to create the most effective environment
for the nitrification process to take place. The media is
engineered in a wheel shape and is slightly positively
buoyant, allowing a small amount of water flow created
by adding air to the process) to circulate the media
throughout the vessel.
Oxygen and food (ammonia and nitrite) gives the bac-
teria the means to grow, whilst the Kaldnes media pro-
vides maximum surface area for the bacteria to colonise
and produce bio film. It is this process, which removes
harmful ammonia and nitrite from the water. As the
Kaldnes media chaotically circulates within the bio tank,
it causes old dead bacteria/bio film on the outside, to be
removed making space for new younger heavier feed-
ing bacteria/bio film to colonise. Within the wheel, is a
protected surface, which enables colonies of bacteria to
naturally follow their life cycle, maturing and dying, in turn
fuelling the latter stages of nitrification conversion proc-
ess. It also assists in the breakdown of any small particles
passing through from the mechanical stage. Therefore,
the Kaldnes media maintains both a young biofilm & a
maturing bio film providing a more consistent filter per-
formance, whilst improving water quality, encouraging
healthier Koi and aiding in reducing green water and
blanket weed. Due to chaotic movement of Kaldnes K1
media, the process is self-cleaning and requires no main-
tenance. This allows the filter to reach optimum effective-
ness without the disturbance of periodic maintenance,
avoiding unnecessary loss of bacteria within the filter
preventing high levels of ammonia and nitrite within the
water. The other major benefit of Kaldnes K1 media is the
huge 'active' surface area available for the bacteria to
grow on compared to other types of media. This feature
allows for smaller filter design, e.g. the Nexus, whilst provid-
ing increased biological efficiency.
How it all works
Maturing the Kaldnes bio-media is important. The
maturing process needs monitoring closely to ensure that
levels of pH, ammonia and nitrite are within acceptable
parameters for your fish. Usually, within 2 - 10 weeks the fil-
ter will be effective and the parameters should be within
3 Close off the feed to the
biological chamber by
inserting the isolation pipe
into the centre of the
“Eazy”, ensuring that the
rubber flange engages
within the Nexus centre
spigot (Fig.23).
4 Close the inlet to the Nexus by
using the inlet slide-plate sup
plied with your Nexus. You
should now have isolated
your “Eazy” from the system
(Fig.24).
5 Open the air valve
until the Kaldnes
in the “Eazy” is boil
ing.
6 After the “Eazy” has been boiling for a minimum
of one minute, open the valve to waste drain
from the central Nexus chamber.
7 Once central chamber has drained, close waste
valve.
8 Remove the Isolation pipe
9 Close the airvalve.
10 Remove the Nexus inlet slide-plate allowing the
nexus to refill.
11 Restart the circulation pump.
Cleaning Pump Procedure
1 Close single union ball valve on inlet
pressure line (supplied)(Fig.26).
2 Close off the feed to the biological
chamber by inserting the Isolation
pipe into the centre of the “Eazy”,
ensuring that the rubber flange
engages within the Nexus cen
tre spigot.
3 Re-open inlet valve until the water
level within the Nexus central chamber is level
with the overflow, close inlet valve. It is essential
that this water level is maintained to allow
efficient cleaning.
4 Switch off the pond pump.
5 Open the air valve until the Kaldnes in the “Eazy”
is boiling.
6 After the “Eazy” has been boiling for a minimum
of one minute, open the valve to waste drain
from the central Nexus chamber.
7 Once central chamber has drained, close waste
valve.
Nexus Eazy Rev. 1.04 page 7
Illustrated above are the different stages of maturity
that will be experience during the first few months.
Fig. 23
Fig. 24
Fig. 25
Fig. 26

acceptable levels, depending on
temperature and stocking levels.
Bacteria grows faster in warm
water. E.g. a pond at 5 Celsius will
have a very low bacteria count
and a slow growth rate. Therefore
temperature is important in reduc-
ing the time for a bacteria colony
to develop.
Bacteria require food to live otherwise it will starve. The
food for bacteria is liquid and solid waste produced by
fish. Therefore higher stocking levels will provide more nu-
trients for the bacteria and help it to establish a colony.
The liquid waste is called ammonia and is the food for
the bacteria. Solid waste is broken down to ammonia,
but a Koi keeper is better off removing the solid waste
through settlement. The fitting of an Answer 325 filter into
your Nexus 200 filter will improve this dramatically.
The ammonia reducing bacteria, nitroso-monas, pro-
duce an end product called nitrite, which is again
potentially toxic to fish. This is controlled through estab-
lishing a large nitrobacter population to convert nitrite
to the end product, nitrate. The effect of nitrate is less
harmful than both ammonia and nitrite. However if
nitrate levels are allowed to rise above 50 mg/L pond
keepers may start to experience green water & blanket
weed. The Kaldnes Moving Bed Process™ is very useful
in controlling these levels as it has the
highest removal rate of any submerged media on the
market.
Nexus Eazy Guarantee
This product comes with a 2 year warranty, which is
valid from date of purchase. Proof of purchase will
be required.
Any unauthorised repairs, modifications or
alterations to this unit will invalidate the
warranty.
Evolution Aqua accepts no responsibility or liability
due to accident, improper installation or misuse.
Liability is limited to replacement of the defective
parts. This guarantee is not transferable. It does not
affect your statuary rights.
If there is a warranty issue please contact
Evolution Aqua’s Technical Service
department.
Claims for transport damage shall only be recog-
nized if the damage is reported within 24 hours after
delivery and confirmed by the carrier.
Evolution Aqua reserve the right to change this
product specification without prior notice.
All products designed to ISO 9001 and manufactured to ISO 9000
Patent Information: GB2.293333B; WO/00 61258; PCT/GB01/05533;
PCT/GB01/05549; 0750591;
0575314; 5,543,039; 5,458,779; 6126829; 689246; 2119893; 3183406
Nexus Eazy Rev. 1.04 page 8
Distributed by:
Evolution Aqua Ltd
Evolution House, Kellett Close, Wigan, WN5 0LP
United Kingdom.
UK
Sales: [phone]
Technical: [phone]
e-mail: [e-mail]
Web: www.evolutionaqua.com
Europe
Germany
Unique Koi
Rauhe Strausse 36, D46459 Rees,
Germany
Sales: [phone]
Fax: [phone]
e-mail: [e-mail]
Web: www.uniquekoi.de
e-mail: [e-mail]
Benelux, France, Spain and Italy
Smulders BV
Postbus 1022, 6235 ZG Ulestraten,
Netherlands
Sales: [phone]
Fax: [phone]
e-mail: [e-mail]
Web: www.smulders.nl
e-mail: [e-mail]
USA & Canada
Pond Wise Inc.
429 Shields Rd, Huntsville, Alabama,
35811 USA
Sales: [phone]
Fax: [phone]
e-mail: [e-mail]
Web: www.pondwise.com
e-mail: [e-mail]
Asia
Max Koi Farm
251 Neo Tiew Cresent, Singapore 7
Singapore
Sales: [phone]
Fax: [phone]
e-mail: [e-mail]
Web: www.makoifarm.sg
e-mail: [e-mail]
Australia
Aussie Koi
PO BOX 663, Bulimba 4171, Quensland
Australia
Sales: [phone]
Fax: [phone]
e-mail: [e-mail]
Web: www.aussiekoi.com
e-mail: [e-mail]
South Africa
Cape Koi Aquarium
PO BOX 1312, Brackenfell 7561,
South Africa
Sales: [phone]
Fax: [phone]
e-mail: [e-mail]
Web:
e-mail: [e-mail]