There are three main kinds of filtration we need to deal with Koi Ponds.  Biological, Mechanical, and Chemical.  All three are equally important to the well being of the koi and our viewing pleasure.  Here is a brief introduction to Koi Pond Filtration.


        This is the trapping of solids suspended in the water in some type of mechanical or settling filter, where as we can at our opportunity remove them from the water by dumping, back flushing, or rinsing out mats.  There is nothing made that will trap and remove solids all in one.  It’s up to us as koi keepers to physically remove the waste out filters have trapped.        In most ponds water will be removed from the pond by “Bottom Drains” and “Skimmers”, where the solids are then settled out of suspension or trapped and held in some kind of fine filter media until we physically remove it.  The Bottom Drain will draw out heavier than water solids that collect on the bottom and the skimmer will skim off debris that is floating on the surface and also skim off the organic film that will develop on the surface.  These filters can be gravity flow before the pump, pressure fed after the pump, or both.


        In our ponds we will culture living aerobic bacteria that will break down the ammonia and nitrites the fish produce.  The aerobic bacteria is just that, “Aerobic”, or oxygen loving.  This bacteria wants an oxygen rich environment with a lot of surface area to colonize.  The bio filter should come after the pre filter or settling filter.  There are many different media that can be used for a bio filter, far more than we can list here.  But in all cases the bio filter should utilize an air pump to saturate the water with oxygen.


           Chemical filtration is usually something we flow the water through or around like Carbon.  I also put UV sterilizers in this class.  The UV sterilizer is a germicidal bulb that will kill all micro organisms as they pass by it.  

we now carry the full line


Bead Filters

The only Bead Filter made with Multi Port Valve Bypass for reduced back pressure and greater flow. Meaning you can now use a smaller pump for reduced operating cost. Because of so many sizes and versions please call for exact recommendation and pricing.


Nexus Filters


The Nexus Eazy is Evolution Aqua’s exciting new filter system.  It incorporates the industry proven Kaldnes Moving Bed technology coupled with the innovative Eazy mechanical filter.

Combined, they provide outstanding water clarity and quality, pump or gravity fed.  Extremely easy to clean and maintain, with minimal running costs, the Nexus Eazy system is designed and built to last a lifetime.

How the Eazy works – The Kaldnes is retained in a stainless steel basket and has been proven to trap incredibly small particles of waste. Cleaning the Kaldnes is a simple matter of turning on the air tap to the settlement area thus agitating it and causing the waste matter to be dislodged from the media so it can be drained to waste.

Nexus Eazy systems are complete units and include the Nexus body, Eazy central vortex, air backwash line, air diverter valve, unionized ball valves to waste, and Kaldnes media for both the Eazy (static Kaldnes) and the bio-reactor (fluidized Kaldnes).

The Nexus 200 Eazy and Nexus 300 Eazy are the same system in 2 sizes for different pond volumes.

Nexus 210 Eazy, 50″ wide by 32″ high, 2640 gph max flow, for ponds up to 4700 gallons.

Sale Price $1940.00

Nexus 310 Eazy, 57′ wide by 40″ high, 3960 gph max flow, for ponds up to 8900 gallons.

Sale Price $2695.00

Lid for Nexus 200, $215.00

Lid for Nexus 300, $230.00

Extra Media for Nexus, $99.95 per 1.77 cubic foot bag

Eazy pod


A low priced, smaller version of the Nexus Eazy, the world’s number-one professional koi filtration system.  The all new Eazy Pod is a complete filter system for koi ponds up to 2,500 gallons, or water gardens up to 5,000 gallons.

Utilizes proven Eazy 200 + Kaldnes media

Provides excellent water clarity and quality

Quick and easy cleaning with no wet or dirty hands

Air backwash

Complete with connectors for pipe up to 3-inch

Small size… only 23 inches tall and 23 inches wide

Works equally well in either pump or gravity configurations

The Eazy Pod is also an excellent filter selection for quarantine systems, as a pre-filter, for use on skimmer lines, for adding additional biological capacity, or as a polishing unit at the end of your filtration line.

Sale Price $745.00


Cetus Pond Sieve


The Cetus sieve is a totally new, bow screen pre-filter, made using the latest rotational molding technology. With all of its benefits and build quality, it is undoubtedly the best of its kind on the market today in terms of quality and performance! It is designed to efficiently and effectively remove large amounts of mechanical waste from a pond. It can be set-up gravity or pump fed and has many benefits over the original bow screen technology.

This Cetus has a variable inlet height using the unique patented Pondflow regulation system – for use when gravity fed. This allows water levels within the pond to drop without causing the circulating pump to be starved of water. The Cetus will allow a skimmer or a bottom drain to accept vast amounts of waste without excessive cleaning needed to be carried out. The water must then be pumped to either a normal filter above pond level (Nexus Eazy/Eazy Pod) or to a pressurized filter.

If pump fed, the sieve is placed above pond water level and then the exit water is gravity dropped into your main filter.

It is advised that all pressurized filters be pre-filtered using a Cetus to reduce excessive backwashing and maintenance due to heavy solids.

Can be gravity or pump fed Perfect fit screen so no waste can bypass Totally reliable and simple to install Plug and Play – comes with flexible boots to connect to pipe work Greatly reduced backwashing / maintenance of pressurised filters Robust one piece mould –no welded joints – no leaks! Large waste collection area which slopes to sump outlet Ideal for mechanically filtering skimmer lines Patented float that gives constant flow for gravity-fed level fluctuations Maximum flow rate 18,000 litres per hour Tri-slot 300 micron wedge wire screen in 316L stainless steel on 100% of surface area

Increased levels of oxygen

Technical Information

Max Flow: 4,800 US gallons/hr
Inlet: Gravity-fed 4 inch, Pump-fed 2 inch
Outlet: Gravity-fed 1.5 inch, Pump-fed 4 inch
Outlet Waste: 3 inch
Height: 37.2 inches
Length: 33.5 inches
Width: 22.4 inches
Screen: 300 micron

Gravity fed, $1150
Pump fed, $1250

Aqua Forte Ultra Sieve 111


UltraSieve III:
Twin inlets (4inch).
Multiple inlets possible.

Patented flow regulation.
Extra large waste outlet, incl. 3″ slide valve.
Strong polypropylene house.
Improved edges around sieve.
Maximum flow of 7900 gph
Screen: 300 micron.


Filtration Kits

In many cases the average pond owner can build their own filtration (Do it Yourself, (DIY) for far less money that buying a production made filter and by doing so, end up with a better filter.  One of our specialties at High Desert Koi Ponds is building all our own filtration for our custom pond installations, and also offering “DIY Kits” for the pond owner who wants a little help doing it them selves.

Fluid Bed Filter Kit

Completer Fluid bed Filter ready for Media


Fluid Bed Filter Kit


The fluid bed filter is what we feel the best Bio Filter you can build.  Basically it is a 55 gal barrel with an air diffuser in the bottom aerating the fluidized media as the water passes through it.  The media commonly used is K-1, or Bio Flo-9, a small media that is lighter than water, has a tremendous amount of surface area for the bacteria to colonize, and will fluidize or boil easily as air is added in the bottom of the barrel.  The Fluid Bed Filter Kit has 3 inch water inlet and outlets and can be gravity fed or pump fed.  The DIY Kit comes with a 9 inch air diffuser and bulkhead fitting, two 7 inch strainer balls with bulkheads for going through the sides of the barrel, and a tube of PL polyurethane adhesive.  The pond owner supplies the barrel, air pump,  and media of choice.  Or we can also supply media and air pump.  This basic Bio Filter Kit will also work well with solid media like strapping or mats.


K-1 floating Media for Fluid Bed Filters, $115.00 for 1.77 cubic foot bag

Dolphin AV-60 Air Pump for above Fluid Bed Filter, $159.95
Medo LA 45 air pump for above Fluid Bed Filter, $249.95

Sand/Gravel Filter Kit
Strapping Mech/Bio Filter Kit

Sand/Gravel Filter with Blower


Sand/Gravel Filter Kit


The Sand/Gravel Filter is a final stage fines filter that must be pump fed.  The water from the pond after going through settling and bio filtration then goes to the pump and to the sand/gravel filter, where the last of the solids and fines are removed from suspension.  Then back to the pond via TPRs or Water Fall.

        The sand/gravel barrel filter has an air manifold in the bottom of the barrel with a one HP spa blower mounted to it.  There is a grate on top of that that has progressively finer sizes of gravel and then sand.  The water flows in the bottom from the pump, through the gravel and sand, and out the top through one of two 3″ outlets.  The layers of gravel and sand will trap fines as the water passes through and give you polished water, or water that is “Gin Clear” as we say.  When you want to clean the filter all you do is plug (included with kit) the 3″ outlet to the pond, open the 3″ outlet to waste, and turn on the air blower.  The air blowing in the bottom through the air manifold will dislodge all the trapped waste and solids and will flow out to waste.  When clean, just shut off the air blower, allow the water to run clear, and switch it back to the pond.  It’s that simple.  This filter will provide some biological filtration also.

        The Sand/Gravel comes complete with everything you need except the barrel, the sand and gravel, and air blower .  Included in the Kit is the 2″ shower drain inlet fitting, the air blower manifold, 3″ inlet and outlet fittings, 3″ plug, and a tube of PL Polyurethane adhesive.  


The Mechanical/Bio filter is built the same as the Sand/gravel filter but instead of filling it with layers of gravel and sand, you stuff it full of poly packaging strapping. The poly strapping works very well as a bio media with a lot of surface area and will trap a lot of fines. The trouble with most strapping or static bio filtres is back washing alone just will not dislodge the trapped dirt. This filter has the air blower manifold the same as the sand/gravel filter so when the strapping needs cleaning you blow it out the same as the sand/gravel filter. Much better cleaning than back flushing.


Air Blowers


NOTE, the power cord does not come with a plug, you must wire a plug on.

1 HP $129.95
2 HP  $149.95

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