Water quality and healthy Koi


DIY and how-to

Colourful koi carp swimming in a pond.

Water quality and healthy Koi

Good water quality is the key to successful Koi keeping. Koi are ‘open’ systems. In fact it is often said in Koi circles that Koi keepers don’t actually keep Koi at all – they keep water. The Koi in the pond are a happy side effect of your water-keeping abilities.

If you have a poor environment you will have a poor quality of life and in many instances, no quality of life. Koi ponds are natural living, breathing entities as much as the Koi themselves and building up a stable environment can take some time. Throughout the process the aim is to have water quality conditions that best suit the Koi.

Remember that a 30% change in your water will have a 30% effect on a system. That  (in aquatic terms) is a massive change. When you are trying to get the bio media and bio film to optimum efficiency in a new pond, a large water change every week is not going to solve your problems. With new water you run the risk of adding unknowns to the pond, that may well be the contributing factor to the pond not stabilising in the first place.

Sometimes you have to leave well enough alone, even if the pond looks ugly. Measure the critical water parameters – ammonia and nitrite – regularly and if these are at measurable, but acceptable levels, leave the pond alone. It is more important to allow the pond to reach stability than it is for it to look good. Once the pond has stabilised, then by all means work on getting the water crystal clear.