Common diseases in aquarium fish

Even if you take special care in maintaining your aquarium, it can happen that your fish are affected by diseases. It is important to act quickly to spot the symptoms and treat them as soon as possible.

White spot disease

Your fish has caught a parasite that lives deep under its skin. Speed is of the essence, as white spot disease can quickly become fatal and the parasites can multiply quickly to infect your other fish.

The fish suffers from breathing difficulties, you can observe it coming to the surface with its mouth open. Whitish spots of a few millimeters appear all over its body. It mainly affects neglected freshwater fish. As it is contagious, it is important to isolate the infected fish. If you can, you must increase the water temperature. You must clean all the corners of your aquarium and change the water.

Fin rot disease

A whitish line appears on the fins of your fish due to a bad ecological balance of the aquarium. You must quickly review the parameters of your aquarium and improve them. Often, this is due to a high nitrite level. It is imperative that you place your fish in quarantine in another aquarium. An antiseptic solution may be dissolved. However, you must act quickly. The fins of your fish will gradually become frayed and perforated.

Fish fungus

The infection is due to fungus that appears as a result of injuries, too cold water or a fight. The symptoms are visible: a whitish coating that disappears when taken out of the water, loss of appetite and apathy. If your fish is affected, it will seek isolation in a dark corner of your aquarium.

To treat it, change the water in your aquarium and increase its temperature. To disinfect fungus, swim your fish for a good half hour in slightly saline water or potassium permanganate and ask about putting a fungus killer in the aquarium.


This disease is clearly related to improper feeding. Your fish will lose weight and start to lose its coloration. If you don’t treat it quickly, it may suffer from respiratory problems, have holes in its fins and its spine may become radically deformed. Your fish loses the desire to swim and stops moving. It just floats.
To treat it, you’ll need to change its diet immediately and give it vitamins.

Fish hypersensitivity

This infection is often caused by bacteria, but scientists are very undecided on the issue. Your fish’s belly starts to swell, tearing off its scales, its eyes start to protrude, it loses control of its movements and it is apathetic. The life of your fish will depend on your speed. You must quickly treat your fish with nifurpirinol. You can salt your aquarium to keep your fish hydrated.

You must therefore remain attentive to the slightest physical or behavioral changes in your fish. To avoid the development of these diseases in your aquarium, you must regularly clean it, check the parameters and adapt them if necessary, check the water temperature and choose a food adapted to your fish.