Koi

I keep kois while I was in Malaysia. I sold all my kois while I moved to Australia. The reason for me to sell them is to let them have a good owner who can take care of them. Otherwise they will die soon. I now reside in South Australia. Koi like carps are pest here. It is illegal to rear them.

Kois are stunning and beautiful fish. I bought them at less than 100mm and manage to grow them up to 600mm. Due to the limited size of my tank, they won't grow any further.

Keeping koi is a hobby of science. The challenge of glooming the fish is not what you feed them or how you take care of them. It is water treatment. Koi is a very dirty fish. They eat a lot and also poo a lot. The chemistry lie in converting the ammonia to nitrate in a fast cycle so that the water register zero ammonia, nitride and nitrate. Otherwise the ammnonia will kill the fish and nitrate will cause algae to grow in the water and the water turn green pea colour within a day. You take care of the water and the water will take care of the fish.

What is the magic gadget that will take care of the ammonia? The answer is bio filter. The filter is a separate tank about 30% the size of the koi tank. It has 5 compartments. Three compartments are used to house the Japanese mat, one for coral and another for pump. Bacteria live inside the Japanese mats and they are working on the conversion. The end product nitrate will be absorbed by water plant flooding on top of the surface. I also included water lily and some water plant in the main tank to absorb the nitrate. Keeping water lily with koi is a challenge as koi treat them as food and they like to dig the water lily up and eat the roots.

Maintaining the bio filter require the skill of a plumber and electrician. All pipe works are DIY. The pump fails periodically and I have to replace them. It is an expensive hobby. The koi if Japanese breed is not cheap. I have a combination of local and Japanese breed. However it is worth it. Looking at the koi swimming is relaxing and it make one to relax and enjoy the peace the fish bring to you. The kois are like ladies in beautiful kimono. I have Sanke, Showa, Tancho, Shushui, kohaku, ogon etc. Most of them are about 600mm long.

I hope the new owner treat them well. I have sold them for two years.