Koi & Goldfish are 90% water (people are only 65%)

Koi cannot isolate themselves from their environment. Vital substances that sustain life are continuously exchanged between the Koi and the water oxygen, wastes, carbon dioxide, salts and minerals etc.

This life long exchange of various substances between the Koi and its habitat takes places through a thin semi permeable membrane. Semi permeable means that some substances can only pass one way through the membrane.

Koi can not selectively choose which substances it will allow to pass through the membrane, much though that would be to its advantage. The semi permeable membrane has been developed over millennia of evolution, evolution that has taken place in natural lakes and rivers, not in Koi ponds! This means that the process has assumed that conditions in lakes and rivers will be the ones that Koi are reasonably going to be expected to have to deal with.

Conditions in lakes and rivers are stable eco systems because of their size. Large fluctuations in concentrations do not occur, and if they do it is a very gradual process over decades that allow the Koi to adapt or die. In a pond however, conditions can fluctuate wildly in the space of a day, leading to death and destruction.

Fluids that are in close contact with each other tend to mix. The fact that there is a membrane separating the Koi from its watery environment is not sufficient to prevent a case of whats in the water is also in the Koi! Diffusion is the process that allows the Kois internal fluids to be highly influenced by those external to the Koi.

Therefore:

1. If you change the environment, you change the Koi.

2. The bigger the pond, the more stable it is likely to be (the more capacity it has to absorb changes)

3. Fish can only adjust to changes in their environment in a restricted fashion and over a small tolerance or range

This then is the challenge of Koi keeping. The maintenance of water quality that is consistent, stable and predictable.

The products that HappyKoi.co.za distribute will help Koi keepers achieve exactly that. They perform better and deliver a better water quality that is more stable and more predictable. They offer significantly less maintenance from the Koi keeper and they will afford him the opportunity to keep Happy Koi for many years to come better than any other product can.

They also offer you the opportunity to make good profits, and to grow the hobby with more contented Koi keepers and fewer filled in abandoned Koi projects which loses everyone in the industry money.

Differences between life on land and life in water

Fishdoc is an excellent resource in which the concept of treating Koi as open systems is introduced.

In summary the website outlines that fish (Koi) are remarkably well adapted creatures. They maintain no body temperature because unlike land living creatures, fish are remarkably energy efficient.

Oxygen that is available in water to fish can only be accessed once it is dissolved in the water in which the fish live.

Whilst water is a remarkable solvent, being able to dissolve almost anything, water can only contain about 9% dissolved oxygen. Compare this to the air that we breathe which comprises our external environment and in which the oxygen content is 21%.

Add this to the fact that water is 800 times denser than air and that oxygen dissolves into it very slowly and you can appreciate the efforts that fish have to go to in order to just get a decent breath! In the same way that we do, fish produce carbon dioxide as the by product of the respiration/metabolic processes.

Koi are no different to any other fish. Their food needs are similar to other animals in that they require fats, proteins, carbohydrates, minerals, vitamins etc. They have limited access to oxygen which means that they must use it as efficiently as possible.

Because they are in constant contact with water they also need to deal with the constant diffusion and osmotic processes that take place. Osmosis, the movement of water from a location of higher concentration to lower, requires energy. Energy requires oxygen. Imagine a fish had to not only control this process, but also generate its own body heat. It simply could not get enough oxygen from its watery environment to make this feasible.

Water fortunately has a high resistance to temperature changes. It takes a lot of energy to heat water and relatively speaking water can hold its temperature in colder conditions for a lot longer than other substances of similar chemical composition.

What does happen as water temperature drops is that the metabolic processes in our Koi slow down. Conversely as the temperature rises, the metabolic processes speed up and in the case of Koi, feeding rates can get to impressive levels.

The gills of a fish are highly efficient oxygen extractors and the membrane separating the water from the blood supply is often only one cell thick. This is tiny and represents precious little protection for the fish in the event that things in the pond water turn nasty. In turn, anything that affects the gills of a fish can have devastating consequences.

The rule of diffusion is a critical one to understand properly when it comes to understanding the processes that happen in a Koi pond.

Simply put ... Substances will diffuse from one area of greater concentration to an area of lesser concentration in an ongoing process until equilibrium is reached.

Osmosis and koi and why they urinate continuously in the pond water

This may sound like a mouthful but consider a cup of hot coffee with a spoonful of sugar at the bottom of the cup.

As the sugar dissolves into the coffee it is at its highest concentration closest to the solid sugar pile. This is perfectly logical.

This concentrated sugar then diffuses into the coffee and over time eventually once all the sugar has dissolved the sugar concentration in all parts of the coffee mug will be equal. This is known as equilibrium.

It is important to understand that at all times, all substances and properties (such as temperature and pH) in a Koi ponds seek to be at equilibrium. i.e. at equal concentration. It is the ideal natural state and there is a constant push and pull in order to get there. The fact that equilibrium very rarely happens is not important. What is important is that things try very hard to get there.

Osmosis is exactly the same process as diffusion. It is a term that refers specifically to water diffusion which is why it has a special name. Water will diffuse from areas of high concentration (i.e. pure water) to areas of low concentration (water with a lot of dissolved substances in it), in exactly the same way that the sugar dissolves into your coffee.

This means that even if the sugar decided to ignore physics for a while and not diffuse by itself, the water in the coffee would do the job for it and eventually the sugar concentration would be the same in all parts of the coffee due to the water diffusion process, which we call osmosis.

Now this is fine and well if youre a cup of coffee. Imagine now that youre a Koi. Your salty blood that is separated from the pond water by a membrane one cell thick is going to have a lot of water zipping across that membrane due to osmosis. Your blood is salty, the water is not, hence the natural osmotic process takes place.

If the Koi did not get rid of all this extra water through constant urination it would explode. So this means that the water in the pond is being constantly circulated through the Koi. Can you see how important water quality is to successful Koi keeping?
 

Article by Wiliam Kelly happykoi.co.za