A Guide to Modern Koi Pond Construction
Filter media
A few years ago there were many types of filter media being used, but now the following is those generally being used:-
- Brushes
- Flocor
- Alfagrog
- Japanese matting
- Kaldnes K1
Brushes
Brushes are very efficient at removing debris and blanket
weed, and were very popular until a few years ago.
Unfortunately they need regular cleaning and are very time consuming, and
now many koi-keepers have removed them from their systems. After a while
they can be very difficult to clean around the steel spine.
Many people use Flocor in the first bay, or now The
Answer is considered
a good solution to preventing solids from entering the filter.
Flocor
Koi keepers usually put them in bags so that they are easy to remove and clean. One way of doing this can be seen here.
Alfagrog
Alfagrog is a volcanic rock and is still a favourite with many koi
keepers.
This is also quite heavy and very rough to the hands so many koi keepers
put it into net bags which are obtainable from most koi dealers.
Note. The coins in these photos are 24mm diam.
Japanese matting
In the last few years Japanese matting has become very popular, and used
either for the full system, or in one or two bays in conjunction with any
of the media shown above.
This matting needs heavy aeration, and has proved to need very little
cleaning.
It is usually used with a depth of about 8 inches and fitting of a new
cartridge into a chamber can be seen here.
Kaldnes K1
Kaldnes K1 media has the benefit of a huge active area for the bacteria
to grow on. It needs heavy aeration and works on the moving bed process.
It is supplied with the Nexus units, but a lot of koi-keepers are now also
using it for the first bay of a multi-chamber filter system. It is very
effective for removing ammonia and nitrites.
When used
in an existing chamber some stainless steel or plastic grids are necessary
to stop the media disappearing down the drain or through into the next
bay.
Filter foam
Filter foam is usually used in three layers and is often used in smaller filter systems, but is not suitable for the large filter units discussed here as they would require cleaning almost every day, and eventually they have to be replaced. It can easily block and reduce the flow of water and then causing the pump to run dry.
We will now move on to the Pump chamber.
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.