Your Koi have to live and grow in the water you provide for them.
Your pond/pool is not a natural environment, it is an artificially created ecosystem
Any water exposed to the sunlight and air will become ALIVE and polluted, not just from the detritus and the excreta produced by your fish, but also as a result of the living ecosystem that you need to create in order for them to survive.
Because it is a living system, the chemistry of your water will constantly change and without proper management, can become lethal to KOI.
THE NITROGEN CYCLE
Water chemistry is not just about what you can see with the naked eye,
The clarity of the water is NO indication of the health of your system. Green can be good, and clear water can be deadly, it all depends on what the chemistry is like on the day, at the time you test.
A suitable filtration system for a koi pond will have two main functions
- To remove solid debris and waste matter from the water
- To remove harmful chemicals that are produced by the fish and other living things in your pond system
Here we are concentrating on water chemistry. There are many different chemical pollutants we can test for.
THE biggest problem in your system will be the fact that you keep koi and feed them to keep them healthy and growing. This will pollute your water in two ways
- FIRSTLY, the solid waste you can see (fish waste etc)
- SECONDLY, and more deadly, the invisible dissolved waste you can’t see (mainly ammonia excreted from the gills during respiration, and from the kidneys during digestion and metabolism of food etc)
This SECOND pollution will show up on testing for AMMONIA, NITRITE and NITRATE in your water.
Ammonia is deadly to Koi and will be oxydised to NITRITE which is also deadly to Koi but this will then be reduced to NITRATE which is the natural end product of the Nitrogen cycle – NOT so toxic it’s what the plants/algae need to grow. THIS will all happen in your pond’s biological ecosystem – mainly in your FILTER, but to some extent in all areas of the pond and pipework.
We have a more in-depth paper explaining the Nitrogen Cycle on our website:
The other things we need to test for are the PH and Hardness of the water
The Ph is how acid/neutral /alkali your water is.
Ideally, for Koi Health it should be between 7 and 8.5 on the chart, but it will go up and down all the time.
The Hardness of the water is caused by the amount of dissolved minerals in the water, which is required to help “buffer” Ph swings. Limescale is an indication your water is “Hard” which means it has natural “buffers” in the water to stop the Ph going too low, (too Acid)
CHLORINE – though not included in the basic test kit, is also something that koi keepers need to monitor.
Concentrated levels of chlorine kill fish and other aquatic life-forms
Water treatment facilities use chlorine to treat drinking water and make it safe for human consumption – to reduce bacteria and viruses. It can combine with certain compounds and chemicals (that might be present in your water) forming trihalomethanes, a family of compounds which can be carcinogenic.
Consequently, many water companies have switched from using chlorine to using chloramine – a compound containing both chlorine and ammonia. It is much more stable than chlorine, but it poses a significant headache for pond owners as it is harder to get rid of.
So, this means that chlorine can be introduced into your pond whenever you do water changes or top ups.
Even when koi and other pond fish show no apparent ill effects from untreated water, it doesn’t mean the chlorine isn’t stressing or harming them. It is important therefore to monitor the levels of chlorine in your pond water.
We have a separate paper, explaining this in more detail on our website:
THIS CAN BE VERY CONFUSING IF YOU ARE NOT USED TO UNDERSTANDING WATER CHEMISTRY, BUT IT WILL SOON BECOME SECOND NATURE TO YOU. SO MUCH SO THAT VERY SOON YOU WILL JUST LOOK AT YOUR SYSTEM AND YOU WILL “KNOW”
We are always here to help you understand and to help put things right if they go wrong.