Preparation for your new Koi

Before your new fish arrive, carry out water tests to make sure water parameters are safe before your new fish is introduced. You also need to ensure that the existing population of fish are not harbouring harmful parasites by carrying out skin scrapes, examining the mucus under a microscope and treating accordingly.

More information about safe water parameters and carrying out skin scrapes can be found here: https://cuttlebrookkoifarm.co.uk/pages/diagnosing-and-treating-sick-koi

Moving to a new environment is stressful

When a fish experiences acute stress, such as moving to a new environment, their body releases hormones and neurotransmitters that make the fish breath faster, over-hydrate and lose salt. This can lead to an osmotic imbalance, the most life-threatening impact of stress. Stress reduces the effectiveness of any animal’s immune system, including fish, making it more susceptible to infection or to the effects of a poor environment. Poor water quality or parasite infestation can cause redness of the skin, sulking, flicking or flashing, and if not addressed can lead to death. It could take 1-2 weeks for the new fish to exhibit these signs.

All water regions and ponds have a different chemical makeup, and over time Koi can become acclimatised and tolerant to less than ideal water conditions. Just as people living at high altitude become accustomed to low oxygen levels, fish can become accustomed to high levels of toxic parameters like nitrite over time. This is why existing fish may not show signs of stress from bad water quality, such as high nitrite, but newly added fish will.

What can I do to help my Koi settle into its new environment?

We advise that any Koi purchased from us that are under a year old, as a precautionary measure, are moved into a pond or tank containing salt. This includes our ‘Koi Fry’ and ‘Small Koi’ mixes. There is no harm in salting the pond when introducing fish over 1 year old, as this will also benefit them too. However, we find it more essential for younger fish. Young Koi have an immature, weak immune system (just like any young animal), and as a result often find it harder adapting to a new environment than older Koi.

To counteract the impact of transport stress, we recommend you raise the salt level in the pond to 0.75%. This level should be held for 1 week, before being slowly reduced by your regularly weekly water changes.

For more infomation about salt, please see our article: https://cuttlebrookkoifarm.co.uk/pages/when-and-how-to-use-salt