Why is My Fish Losing its colour?

There can be a number of reasons why fish may lose their colour. These include:

• Stress / Sickness
• Water Condition
• Inadequate Lighting
• Inadequate Diet
• Ageing

Stress / Sickness and the Water Condition can play a major part in the loss of colour in fish. Stress can occur due to change of environment – change in water temperature, pH levels etc. You can find that when fish have newly changed environment they can lose their colour but this may be regained when they become used to their new environment. Toxic nitrogen compounds can cause Stress which leads to a weakened immune system that makes the fish vulnerable to diseases and parasites. If the loss of colour is due to Sickness the most noticeable signs are – not eating, listlessness or no buoyancy control / no balance. This indicates an unhealthy nitrogen cycle and may lead to fish death. If you notice this the best thing to do is to get a water test done. You may find you have high levels of ammonia or nitrite which are harmful to the fish. You can find out more about the ammonia and nitrite levels below and how to correct them.

Ammonia Link

Nitrite Link

Fish have pigment in their skin that reacts to light. When their skin isn’t getting the required light they need or no light at all this will affect their colouring. So they might lose colour or they could turn a white or pale colour. The colour change can be fairly noticeable in fish that are in ponds to those that are in aquariums. For example, we have Pygmy Perch in-store. They are mostly kept in Ponds but for convenience we have a few in aquariums to show to customers. We have a large fish pond that we keep most of the stock in outside. When we fish them from their pond they are a darker silver colouring. When they have been in the aquarium for a period of time under artificial light you notice they start to dull in colour. Natural Exposure from Sunlight helps to develop the pigments which enables them to show healthy colour.

Inadequate Diet can play a part in the loss of colour. Cheaper foods tend to have more filler than the nutrients that are needed for the fish. To achieve your fish’s optimal colouration they need a healthy diet. This will vary depending on the species. Higher Quality Foods such as Saikoh or PondMax Premium have colour enhancing additives.

Old age can cause discolouration on parts of the fish’s body. Old age can also cause them to get a translucent look to their body. There isn’t much you can do if the loss of colour is from old age. You can try and help with colour enhancing fish food but this may not have much of an affect.