Prevention is better than cure: this wise old proverb is perfectly applicable
to fishkeeping. Prevention entails daily observation of your fish and their environment,
and this requires a certain degree of knowledge. In the end, the best prevention
comes from maintaining a good balance in the aquarium.
Diseases and their treatment
Generally speaking, there are two types of diseases - infectious and non-infectious.
The former are caused by microorganisms, such as bacteria, fungi, or viruses carried
by the fish. The triggering factors are well-known: stress, bad diet, decrease in
temperature. Some pathogenic organisms have a mixed life cycle: one part on the
fish, one part in the water.
Non-infectious diseases are not caused by pathogenic organisms, but by the environment
(low-quality water, underfeeding).
It is important to avoid any cocktails of medicines and useless or harmful overdoses.
The treatment schedule must always be respected, even if the symptoms quickly disappear.
When taking care of sick fish, it is best to feed them moderately, but with natural
foodstuffs. Once the illness is cured, provide a varied and well-balanced diet,
in order to consolidate the healing process.
HOW TO RECOGNIZE A SICK FISH?
Diseases are not particularly easy to detect, especially if they do not manifest
any external symptoms. However, several indications can lead an aquarist to think
that a fish is sick. These phenomena can be seen in isolation or together.
The bearing of this fish (Macropodus opercularis) and its
siightiy raised scales suggest a poor state of health.
- General behavior: the fish hides, is easily scared, and is stressed out.
- Swimming: uncoordinated, and the fish may scrape against the decor or the
- Feeding: weight loss, refusal of food.
- Breathing: the fish comes to the surface to "stock up" on air.
- External symptoms: white spots, whitish marks, swelling of one or both eyes
or the whole body, bristling scales, several wounds, etc.
AND A FISH IN GOOD HEALTH?
There are two things to take into consideration: the fish's appearance and its
behavior. This requires a good knowledge of its anatomy, biology, and ecology. A
fish in good health has bright colors and sparkling eyes. Its body is not swollen
and its scales and opercula do not stick out. It comes to eat in a normal way, in
terms of both the feeding process itself and the amount it eats. It does not hide
without a good reason.
Bright colors and fully deployed fins are signs of good
The stages of treatment
- Put the fish in a hospital aquarium.
- Raise the temperature to 27-28 °C.
- Stop the filtration, and maybe the protein skimmer in salt water, while
at the same time increasing the aeration.
- Dilute the medicine as required.
- Pour the medicine little by little into the aquarium. It is best to spread
this operation out over a period of at least one hour, or one day when administering
- Leave it to act for the recommended period.
- Empty out half the aquarium, then top up by adding water that is identical
to the original.
- Change 10% of the volume each day for 5 days, always using an identical
- Repeat the treatment if necessary, following the steps above.
- Switch the filter on again and, where applicable, the protein skimmer.
- Gradually reduce the temperature to its original level. This operation must
be spread over 3 days.
- Bring the aeration to its original level. In a mixed aquarium, the process
obviously begins at point 2.
Knowing your fish well - their color and behavior - constitutes
one of the main rules for disease prevention in an aquarium.