Ronnie started collecting Koi about 6 years ago. He and Trish had a large swimming pool of about 90,000 Litres and decided it would be cheaper to put koi in than spend money on pool chemicals. As Ronnie says “how quick we learn”.
The pond was his own design. Kevin Harrison and Brian Welsh helped with the filter design. The circular pond has about 60 Koi ranging in size from 20cm to 70cm.

Ronnie’s favourite koi is a showa –
Trish’s favourite koi is called Spot (a pavement special) but her favourites are Tancho`s

The most enjoyable part of the hobby for Ronnie and Trish is sitting quietly and relaxing at the edge of the pond in the evenings, feeding the fish whilst enjoying a sun-downer.


When Ronnie first started koi were bought from Costa Jackson at Sakura Koi Farm and now he buys from wherever he sees a koi he likes. New koi are quarantined in vats for 3 - 4 months and placed into the pond after scraping for parasites if necessary. As with all new ponds there were problems – the dreaded New Pond Syndrome (NPS). The pond took about 18 months to clear and stabilise. In the beginning Ronnie had huge problems with ulcers etc. Kevin Harrison, Costa Jackson and Raj Lalloo (our current Chairman) all helped overcome the problems. Since the pond has matured and the initial diseases were cured there have been absolutely no problems at all.


One of the changes made from the original design was to modify the main biofilter to make it easier to flush and also change the media from the original crumbly lava rock to a Scotch plastic media.

The koi collection is fed a diet of good quality koi pellets plus lettuce and brown rice.
Standing at the edge of the pond the water it is truly crystal clear with a wonderful sparkle to it. There is a gentle circulation of the water which helps move solids to the drains. The koi are well and happy, growing like hang and are easy to see through a feeding ring which keeps the surface turbulence to a minimum.

Pond Design:
Formal, circular with an island in the middle
Pond Capacity: 120,000 litres.
Construction: bricks and concrete
Sealing: Originally Marble Plaster but a Bituseal was painted over this to seal the pond.

There are brushes inside the vortex tanks. Ronnie has found that the vortexes cannot be flushed completely. When the bottom drains are opened a small amount of solids are discharged and the bulk of the solids remain trapped in the brushes and tanks.

Ronnie invented a vortex flusher. Using conduit piping he made a ring with holes and a stand pipe.
When he wants to clean the vortexes and the drains are open he attaches a hose to the vortex flusher. This water sprays out and is pulled up and down in the vortex to dislodge the solids. This works very well.


System Design Considerations:
Water flow and movement: There are 8 bottom drains of 110 mm each. These are placed around the pond. The bottom drains feed 2 per vortex (mechanical filters). 2 x 110 mm pipes feed off the vortexes to the bio-filtration system.
The inlets to the vortex chambers from the bottom drains have been modified:
The return pipes to the pond through the walls are angled to create circulation around the whole pond.

There are 8 x 100mm bottom drains so the water moves relatively slowly to the filter system. The bottom drains are occasionally isolated and flushed with a large volume of water to remove any settlement.
The mechanical filters (vortexes) are flushed once a week with the valve at the bottom. The vortexes are also flushed whilst the Vortex Flusher is used. They are totally drained and flushed every 6 months.
The biofilter chamber is also give a flush by opening the bottom drains every week then the whole chamber is flushed once a year.

The floor of the pond remains free of organics and solids.