Building a good Koi pond

Many koi-keepers are of the impression that only hobbyists with large ponds can keep high quality koi. We do not believe this is necessarily the case. Keeping high quality koi and ensuring the fish reach their full potential in a small pond is possible as long as some basic concepts and designs are adhered to which ensures good water quality. In our opinion, the factors below should be taken into consideration:-

• The most suitable place for the pond should be in a position whereby the pond is not exposed to the sunlight for the entire day. The pond should be exposed to sunlight a maximum of four to five hours a day.
• The optimum shape for a koi pond should be either round or square (rounded off at the edges). Refrain from building ponds that are long and narrow.
• The depth should be a minimum of one metre.
• Keep the pond and filter system as simple as possible.
• The filtration system should have more emphasis on biological filtration rather mechanical filtration.
• It is advisable that the filter chambers have bottom drains which should be flushed daily. Daily flushing of the filter chambers will ensure that the filter system is not overloaded with fish waste and will require less frequent cleaning and maintenance.
• Ensure that the filter chambers are well oxygenated to promote good filter bacteria.
• Using a constant slow drip which is in place 24 hours, aim to change 10% of the water daily.
• The water pump should turn over the total capacity of the pond in approximately 1 and 1 1/2 hours.

Water Quality

The most important aspect of koi-keeping is water management. As it is often said by many experienced koi-keepers, if you take care of the water, the fish will look after themselves. We would like to share some basic knowledge on water quality:-

• Malaysian water from the mains supply is generally safe to use in our ponds. However, a dechlorinator must be used to take out the chlorine. Chlorine used to disinfect the mains water supply is harmful to koi.
• Koi thrive in soft water. Koi growth is enhanced, colour quality and the shine of its skin will be much better. On the other hand, hard water is stressful for the fish. Koi will have a stressed bloodshot-like appearance on its body and will lose its lustre.
• The optimal PH level for koi is between 7 and 7.6.
• Water has to be clear and not yellowish. An oily appearance and long-persisting bubbles on the surface of the pond indicates that it is the filters should be cleaned.

We wish to stress one last point to note on water quality. Maintaining healthy water is more essential than ensuring water clarity as far as koi-keeping is concerned. Just look at the Japanese mud ponds. Many novice koi-keepers focus on the appearance of the water as they are of the impression that clear water equates to good water conditions for their koi. We wish to stress that clear water does not necessarily mean healthy water. Healthy water sparkles and does not smell. Conversely, unhealthy water is generally dull and smells. Also, healthy water promotes thick and green algae growth on the sides and bottom of the pond while poor water conditions result in brownish algae.

Importance of a good diet for our Koi

In our opinion, the ability to grow high quality koi is 50% genes, 30% water condition and 20% food. Thus, we wish to stress that a balanced diet with the essential nutrients and vitamins is essential for a hobbyist to produce and raise superior quality koi.

Below is a guide as to the daily feeding frequency based on the climate conditions:-

Below 12 Celsius – do not feed
Between 12 and 15 Celsius – feed once a day with low protein food
Between 16 and 20 Celsius – feed twice a day with low protein food
Between 20 and 23 Celsius – feed three times a day with low protein food
Between 23 and 26 Celsius – feed four times a day with high protein food
Between 12 and 15 Celsius – feed five times a day with high protein food

Please note that kois need not be fed until they are full. Kois that are fed around 80% capacity are likely to be more active and healthier in the long run. An indication of an overfed koi is that the eyes bulge out after feeding. Longish looking fish faeces that floats on the pond surface is indication that the digestive system is not functioning properly. In both cases, we would recommend to reduce the quantity of food given.

When producing koi food pellets, each manufacturer will have its own choice of food elements and vitamins which it believes will supply the fish with sufficient nutrients to grow. As the composition of nutrients required by each koi may vary, we would advise koi keepers to vary their purchase of koi food between different manufacturers so as to provide the fish with a balanced average diet.

Koi keepers should tailor the food diet with the appropriate conditions, e.g. using colour supplementing diets as and when the hi of the koi is weak.

In our experience, a superior quality koi fed with good quality food will maintain its excellent body shape whereas average/poor quality koi fed with the same food can potentially become pot-bellied. Also, please do not feed high quality koi with food not made especially for koi as it could result in weakening body colours and poor body shape.

Fish medication

If a koi falls sick, it is not necessary to treat the entire pond. Rather, isolate the koi by placing it in a hospital tank for treatment.

In terms of treating sick fish, the first course of action would be to use salt as it reduces osmotic stress and is generally used for treating protozoan and fungal infections. We would recommend a salt level of 60gm per litre.

Do not use medication on the sick koi unless problem is properly diagnosed. The use of chemicals may weaken the fish and may have long term negative effects on the growth of the koi.