KOI Pond Tips & General Info

Koi or Nishikigoi, are descendents of the common carp. In nature they are brown, but through selective breeding by the Japanese, numerous colors and patterns were developed. Koi normally attain lengths of approximately 2 to 3 feet and weight up to 35 lbs.

Because of their large size, they should only be kept in large Koi ponds of at least 1000 gallons. Koi need very good water quality to remain healthy. Sophisticated filtration systems should be used inside the Koi pond to maintain the Koi fishes' well-being.

When adding new fish to the Koi pond it is important to follow a few simple steps to insure happy and healthy fish.

First, if the Koi pond is new or water has just been changed or added, be sure that chlorine has been removed by using a pond dechlorinator.

Next, place the plastic bag containing the Koi fish into a shady section of the pond. If your pond is in full sun, be sure to cover the bag with a newspaper so the fish will not get to warm. Allow the water in the bag to adjust to your Koi pond water temperature. This may take between 20-40 minutes, depending on the difference in temperature. After the proper water temperature has been reached it is a good idea to further acclimate the fish by opening the bag and allowing some of your Koi pond water to enter the bag.

This will allow the fish to adjust to the pH of your Koi pond. Allow the bag to float another 5-10 minutes and repeat the previous step several times if there is a significant difference. Too great a difference in either temperature or pH can cause your Koi fish to become stressed.

In winter the fish pond or Koi pond slowly shuts down. Any tropical species should be stored in the proper manner for each plant. The fish have greatly slowed their intake of food and their actions in the fish pond.

They will need feeding only occasionally in the south and not at all in the north where the fish ponds freeze over for the winter. In the event that the fish pond or Koi pond should freeze over, a hole in the ice must be maintained for the survival of the fish.

If the hole is not maintained there can be little air/water gas exchange and the fish will die as they continue to respire and use all of the oxygen dissolved in the water of an ice covered fish pond or Koi pond.

A hole in the ice can be maintained using any of the commercially available electric ice melting devices specifically designed for use in pond situations. Never use any device not manufactured specifically for that purpose. Never hit the ice with anything to break it open. The force from the blow will reverberate as shock waves in the fish pond and kill the fish. This is one of the major causes of winter death of fish in home ponds.

Koi need not spawn in order to remain healthy. On the contrary, the process has accompanying dangers to health, color, and patterning of fish which are involved. Under normal pond conditions, indiscriminate and spontaneous spawning may occur, unobserved by the pond owner, and the resulting eggs either are eaten by the adults or disappear down the overflow, particularly when the pond is free of vegetation. When spawning is a deliberately encouraged and planned event, many more considerations are involved.

The number of males to female in mating is controversial. Certainly, a 1:1 relationship has a more predictable genetic outcome than when several males are used. Equally important as a consideration is the possibility that a number of aggressive males may subject the female to injury in their spawning excitement. Under NO circumstance should the ratio ever exceed 2:1. Taken for granted is that fish being mated will be of relatively similar size.