A Guide to Modern Koi Pond Construction
Filter systems
We will now look at the filter system for the pond. This must be considered when you are first designing your pond system, and you must decide on this important item before any start is made to construct the pond.
Many koi keepers can quickly decide on what size of pond they want, but in many cases they do not then have enough space to have a filter system big enough to support their designed pond.
There are several types of filter systems available, but I think we can break them down as follows:
- Prefabricated multi-chamber systems.
- Vortex units.
- Home made filters from concrete blocks.
- Nexus units.
All these are known to work well as long as they are big enough for the
pond so it is up to the individual to decide which they are going to use.
There are several specialist types of filter available, but if
you decide to fit one of these then you need to get the details from the
dealer concerned.
On the right hand side water enters the filter system from either the vortex chamber or settling tank.
The water then goes to the bottom of the first chamber and then raises up through the media grids and the media itself to the top of the chamber. This water will then overflow over the weir, and so to the bottom of the second chamber where the whole process continues as it did in the first bay. When it reaches the last bay it is pumped back to the pond.
When you are deciding on the type of filter you are going
to have then the first decision is whether you are going to purchase
a prefabricated muli-chamber system, a Nexus, or whether you prefer to
build one with concrete blocks and after rendering then waterproof it
with G4 or fibreglass laminate.
This photo shows one type of preformed filter. They are easy to install as they
come as a complete unit with pipes and valves ready for connecting to your pond
and pump pipework.
When you have decided on the surface area of the filter, which should be at
least 30% of the surface area of the pond, then you can start working out the
price for building your own, and also when you have done that you can start
looking at the type of units available. You can then check the cost of each
unit and decide which to use for your system.
This is the other end of the scale, and this shows a purpose built filtration
room belonging to a koi-keeper in the Midlands.
The filtration system consists of four seperate systems each consisting
of one Nexus 300, one large vortex filter with Japanese matting, and a
sand filter.
With a smaller pond of say up to 7,000 gallons then one of these units would be sufficient, and is the way many koi-keepers are thinking at the moment.
We will next look at Prefabricated multichamber systems .
Also check out questions and answers for Filters
This website started with a booklet which I made up originally for the help of those members of the BKKS - South Wales Section who were intending to start building a koi pond, and as the website has expanded more information and articles from other people have been included. This is for general guidance only, and we do not take any responsibility for problems that might occur by following these ideas. It is important that you check out everything in your area, and check on local laws and rules that may apply.