01. Creating the perfect pond environment.

We should never lose sight of the fact that koi are living organisms first, and living jewels second. And koi is just like any living thing in that they demand their own specific requirements for life from their environment. Throughout this series of looking at the 10 steps to successful koi keeping, a number of topics that are key to achieving success with koi will be discussed. Arguably, the most fundamental factor that underpins all others on the road to success is creating a perfect environment (if such a thing can exist) for koi

Get the environment right, and the other pieces of the jigsaw will fall into place. Get it wrong, and our hopes for success will be built on shaky foundations, and history is littered with stories of those who built their houses on sand!

What do we mean by the ‘perfect pond environment’?

At this stage on the road to koi success when discussing the pond environment, we are not yet concerned by the pond’s foundation’s (concrete or clay) but rather the living conditions within which our koi are expected to live, grow, thrive and even breed. Agreed, the practical matters such as the size and type of pond construction koi are important in achieving this, but by even talking about such matters at this stage aren’t we already limiting ourselves by what we want, or can afford.

The best way of really getting to the bottom of what is meant by a perfect environment for koi is by turning koi keeping on its head, by looking at it from a koi’s point of view rather than our own – Quite a challenge! In doing so, we must think like a koi, look at things from a koi’s point of view and ultimately ask ‘what objectives do what koi set us when creating their environment?’ Or put another way if koi could talk, what would be on their wish-list?

The answers might be surprising as well as challenging and are likely to expose us for how koi-orientated we really are, and to what extent we might be keeping our koi in compromised environments to suit our needs as well as theirs.

A little detective work gets us off to a good start when considering what objectives koi set us for creating a perfect environment. Arguably, there isn’t such a thing as a koi’s natural habitat because koi are not a naturally occurring fish. Their wild-type ancestors, the carp (Cyprinus carpio) though does have a natural habitat (even though it has been introduced across the world into non-native, yet hospitable environments).

So in order to be able to satisfy koi, we can use the standards required by carp as a benchmark, but with the proviso that koi are less adaptable and therefore more demanding than carp on account of their inbred and weakened genetic make-up. A greater incentive to get their environment just right.

A stable environment.

This at first might appear to be a contradiction. Carp are probably one of the world’s most adaptable of fish species (and are consequently the most widely farmed) and yet they require a stable environment. Their adaptability is largely attributed to their tolerance of a wide range of temperatures. We should remember that carp (and by default koi) are a warm water fish, growing most efficiently at around 27oC. Their tolerance of such a wide range of temperatures (from near-freezing to over 30 degrees C) does not give us license to subject koi to environmental extremities, but should prompt us to provide them with what nature intended rather than take liberties and provide them with what we can get away with.

A stable environment is one where all water quality parameters naturally resist change because of the characteristics of the environment. But where change does occur, it does so a long natural limits to which koi are well adapted and ‘engineered’. For example, the larger the volume we can offer our koi (they are a lowland lake species) the less likely they are to experience rapid and extreme changes in daily temperature and dissolved oxygen concentration.

A carp is created and adapted for a lowland lake existence, and that is what we should give them. Compare this to a blenny from a rocky shoreline. It is adapted to daily changes on an extreme scale, from bombarding ocean currents at high tide to being stranded in an isolated, overheating of rock pool at low tide. If you asked a blenny what it wanted from a captive environment, it would require what it gets in the wild.

An extensive lowland lake will still experience seasonal changes in temperature of varying profiles depending on the lake’s latitude. Even so, they require and are made to experience a seasonal variance, breeding, growing and resting in response to these cues. If our aim is to achieve a perfect environment, we should also provide our koi with these variations, but in a stable setting.

Carp on not adapted to tolerating poor water quality such as high ammonia and nitrite and should not be subjected to them. Lowland waters will naturally experience some of the highest levels of other solutes compared to other freshwater environments. A lowland system is the area that receives the run-off (and the elements dissolved within it) from the water courses and the land that overlooks it. Consequently, these lakes will typically be hard water areas, high in minerals, with slightly alkaline water.

Each basin will have its own specific characteristics, different from the others, but the levels in the system will be relatively constant. Consequently, koi should also be provided with mineral-rich, slightly alkaline water that is stable within the boundaries of acceptability. Compared to other species of fish, carp can be kept quite successfully within a wide pH range (7.5 to 8.5) as long as that pH is stable.

Food. This is one of the most difficult areas with which to match the experiences of carp in their natural environment. The artificial dry diets that we offer our koi in captivity are formulated to meet their nutritional needs as well as the environmental needs of an artificially stocked pond. Naturally a carp’s diet may contain between 50 and 60% protein. They would happily live off a similar diet in captivity, but we do not offer them such a diet for the sake of the water quality and our pocket. Our artificial diets also substitute a lot of the protein that koi would burn for energy with carbohydrates that burn a lot cleaner than proteins. On the one hand, offering koi artificial diets is a compromise between what we want and what is best for our koi, but on the other hand it allows koi to enjoy precise nutrition every day. But is offering koi such a highly digestible and low-waste diet really natural or again a compromise between what we want (cleaner filters) and what carp are designed for (a high-fibre diet)?

Perhaps one of the starkest differences between an artificial koi pond and a carp’s natural environment is the clarity of the water. Carp are most secure in turbid conditions found in lowland waters. These conditions afford carp with superb water conditioning properties and personify and natural carp environment. And yet we endeavour to keep our koi in ever cleaner and clearer water that allows us to read the manufacturer’s name imprinted in the bottom drain, 6 ft down.

This is purely for our benefit, so we can see our koi, and keep our filter maintenance to a minimum. But what is really best for our koi? We attempt to redress the balance in piecemeal fashion by adding a little clay every so often, perhaps to appease our own conscience as much as make our koi feel ‘at home’. But surely if we wanted the very best for our koi (and in doing so we were genuinely thinking like koi) would we really keep ourselves in perilously clear water?

So in attempting to provide our koi with the environment that they are designed for an thrive best in, we automatically face and number of challenges. The further we depart from their natural environment, the more problems we will face, stumbling at the first step on the journey to successful koi keeping. The sooner we admit that some of the problems we experience in koi keeping we bring on ourselves by providing a compromised environment, the sooner we will get closer to achieving greater koi keeping success.

Differences between the natural and artificial environments and their likely consequences to koi success.

A. Natural Environment vs B. Artificial Environment

The differences and consequences

1. Pond Volume:

Natural: Pond volume is huge

Artificial: Pond volume is limited Smaller volume will lead to variations and instability in water quality. Something that koi will tolerate, but not thrive in.

2. Stocking Density:

Natural: Stocking densities are naturally low

Artificial: Stocking densities are artificially very high This has implications for stress through sheer numbers and competition at feeding time. It also necessitates a filter and recirculating water which in turn leads to clear water.

3. Water Clarity:

Natural: The water is naturally turbid

Artificial: Philosophy that clearer water is better water Removal of suspended inorganic matter from the water can lead to increased stress, and a reduction in a mineral load of the water.

4. Pond Food:

Natural: A naturally high-protein, high-roughage diet

Artificial: A comparatively low protein diet where the emphasis is on and digestibility The artificial diet is formulated to meet the needs of the koi and the artificial pond. Koi do not experience the higher roughage diet for which they are designed. Is this really ideal?

5. Seasonal Cycles:

Natural: Pond experiences natural seasons

Artificial: A heated koi pond attempts to provide koi with the seasonless year Koi physiology can become confused, experiencing daylength : water temperature mismatches, leading to complications such as reduced growth in winter in a heated pond, and female koi entering autumn in a spawn-bound state, not having had the natural environmental cues to spawn.

Kill blanketweed and string algae.