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Swim Bladder Disease causes the classic upside down goldfish. Get a treatment specifically for Swim Bladder Disease from your aquarium supplier or swelluk.com.
Swim Bladder Disease causes the classic upside down goldfish. Get a treatment specifically for Swim Bladder Disease from your aquarium supplier or swelluk.com.

Common Aquarium Fish Diseases


All aquarium fish are susceptible to disease, and unfortunately once it takes hold it can be difficult to shift. Most diseases are bacterial, fungal or parasitic, and are often initiated when fish are stressed, maybe due to an incorrect pH balance or lack of maintenance.

Recognising the symptoms of disease and acting accordingly can save precious time and ultimately fish. Putting together a kit of treatments for the most common ailments is a good idea so that you are always prepared. Swell UK has a wide range of treatments for all manner of diseases, and test kits to monitor water health too.


Parasitic Infection:

White Spot or Ich, as it’s sometimes known, is a parasitic infection that can quickly spread. Left untreated fish can suffocate and die. It can be caused by new, infected fish or decorative items and abrupt changes in temperature.

The symptoms include:

  • The fish will scratch against rocks and décor
  • They may swim in an erratic manner
  • Fins can appear folded against the body
  • White spots appear from head to tail, this is the actual parasite.

It’s a good idea to quarantine effected fish and treat them with the appropriate anti-parasite or malachite treatment. A water change may also be a good idea to cleanse the tank.

Another parasite to look out for is the Anchor Worm. It looks like tiny grey/white worms that burrow into the fish’s skin. A suitable parasite treatment will clear the problem.


Bacterial Infection:

Fin Rot can be both a bacterial and fungal infection. It is generally a secondary infection in fish that are already stressed or sick. Betta (or Siamese Fighting Fish) can be quite susceptible to this, so if you spot the signs, treat straight away.

The symptoms include:

  • White dots appear on the fin (fungus)
  • Fins have a frayed look, possibly look black or brown
  • Base of the fins looks inflamed
  • Pieces of the fin rot or fall off

To treat change the water, and clean the filter out too. Test the pH level of the water and amend accordingly with a suitable buffer. Also treat with a malachite treatment, which is excellent at clearing all manner of problems.

Another common bacterial infection is Swim Bladder Infection. This occurs due to an infection in the fish’s swim bladder, the organ that keeps him upright. Fish can lose buoyancy and actually flip upside down. A specific treatment for this condition is available from various manufacturers.


Fungal Infection:

Cotton Wool Disease is a very common fungal infection. It generally attacks areas that are prone to infection, and has a white fluffy

texture. It is generally caused by previous infections, rough handling and spikes in temperature. Uneaten, decayed food can also be a cause.

The symptoms include:

  • White fluffy substance around the gills, mouth and on the skin
  • Grey or brown patches may also appear.

Quarantine any infected fish, and treat with an anti-fungal treatment or salts. Perform a water change and clean the filter to remove any remaining spores. Also make sure that any uneaten food is removed after a few minutes.


Forewarned is Forearmed!

Most problems can be avoided with regular maintenance. Keep on top of routine water changes and test the pH balance too. A spike in the pH can stress fish and this makes them vulnerable to infection. A suitable buffer to regulate the balance will help.

About David Wharton

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