Preparing mud ponds for koi

At the start of the new season, in early spring, the ponds are drained and allowed to dry out. They are then rotavated and pure lime is added to the mud. This not only kills off any parasites that may be present, but also helps to increase the pH value of the water. The water used to fill the ponds is natural spring water from the mountains which is very acidic. Phosphates and minerals are then added to the base before it is tamped down again ready for refilling. As well as being acidic the natural spring water is so high in minerals that the water turns green very quickly. Chicken manure is added to the ponds a few days before spawning is expected to take place. This produces millions of infusoria (a class of protozoa), a minute waterborne life form that is necessary food for young koi fry. Newly hatched fry need huge amounts of this insuforia to maintain their growth from the time that they hatch. The Tategoi also enjoy this fresh diet when they are returned to the newly prepared ponds after spending the winter inside. At the same time as the mud ponds are being prepared, work is also starting on preparing for the new spawning season. The indoor spawning pools are drained and thoroughly cleaned. Fresh oyster shells are put into the filters as this helps to raise the pH of the water. The indoor pools are then filled with exactly the same spring water as the mud ponds. The brood stock, or Oyagoi are selected and segregated, male and female koi are placed in separate pools.