Caring for Koi

Varieties of Koi

koi varieties

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Protect Koi From Predators

Birds, cats and foxes are the main predators for koi in a residential fish pond. As anyone who has ever had a bird feeder knows, once local birds find a feeding spot, they will continue to come back.

garden-pond-netting.gifThere are actions you can take to minimise the danger to your fish. Ponds should incorporate a deep end that the koi can dive to for safety. Lily pads can provide additional cover as well as placing some sort of shade cloth high above the pond or a mesh near the surface.


Keep Pond Water Chemistry Correctly Balanced

ph-test-kit.jpgInvest is a decent water chemistry test kit. Koi are tolerate of different pH levels, but we recommend that you aim to have the pH fluctuate as little as possible.

Never adjust the pH of the pond by more than 0.2 units per day or else you risk pH shocking the fish.


Koi Pond Requirements

Koi have very different needs to that of goldfish. While goldfish can be kept in shallow ponds, koi need at least three feet of pond depth but ideally even deeper.

Adult koi can grow to be three feet long and weigh 10kg! so plan accordingly when determining how big to build your pond. A koi hobbyist will soon find their collection of koi will continue to increase beyond their intial plans. There are so many colour varieties you will want them all.

Koi are big, eat more and produce more waste than goldfish so be prepared for a larger filter to be required. Ideally as large as your budget will allow, the bigger it is the longer it can go between cleaning.


Sufficient Pond Aeration

As your biological filter uses oxygen to feed the beneficial bacteria it will take a heavy toll on the available oxygen in the water for the koi to breathe. Koi need more of everything than other ornamental fish such as goldfish do. A supplementary outdoor aerator is highly recommended such as the Oase AquaOxy At low levels of oxygen the colours of the koi will be diminished.


Koi Health

Part of having a healthy koi is one who is fed nutritious food. When buying manufactured food, check the vitamins and minerals content. Good quality fish food will produce growth and enhanced colour.

Stress - Stressed koi will have a weaker immune system, provide them with clean water through an adequate filtration system, protect them from predators and do not overcrowd the pond with too many koi.

Monitor for signs of disease

common-fish-koi-diseases.jpgParticularly watch for abnormalities signs of disease at the beginning of Spring. As the temperature increases, diseases that may have lay dorment during winter will activate and attack the fish while their immune system is still weakened from winter. Infected fish should be removed to a separate tank and quarantined to prevent spread to the rest of the pond.

Bacteria, fungus and parasitic infestation are problems that need to be addressed as soon as possible to prevent the loss of a small friend. Delay in quarantine can bring about the deaths of many pond residents.

Koi Medication

Whenever you medicate a pond you are treating all the fish whether they need it or not. Some chemicals can kill the beneficial bacteria in your filter which will result in a sudden increase in ammonia levels.

After treatment, products such as activated carbon can be added to the filter to absorb leftover chemicals. Remember to remove the activated carbon after the recommended time or any rubbish it absorbs will be released back into the pond water.


Koi Keeping Tips

  • Koi will dig in your potted aquatic plants and often uproot them. A good solution is to cover the pots in netting, for example, the netting bags that oranges and other fruit and vegetables are bought in.
  • It is estimated 90% of fish illness is due to an overstocked pond. Too many fish.
  • Most koi skin conditions can be treated with adding a small amount of salt to the quarantine tank water. No more than 2%