Video: Why Do Fish Get Sick?
The resistance of aquarium fish to various infectious and non-infectious diseases depends on the conditions of detention. For example, from nutrition, saturation of water with oxygen, its hardness, dissolved organic and inorganic substances, as well as temperature.
Pisces are cold-blooded creatures. They are very sensitive to fluctuations in water temperature, so a decrease in temperature by only 5 ° C (from the point of view of warm-blooded animals, this is a trifle) causes a cold in the fish. With a sharp drop in water temperature or with prolonged maintenance in such conditions, the fish become lethargic, take poor food. In the event of a significant decrease in temperature, cloudy spots appear on the surface of their bodies - epithelial cells of the upper layer of the skin die off. If you do not take action, destruction will affect all layers of the skin, ulcers will appear.
What to do? Bring the water temperature (gradually, without sharp fluctuations!) To the required temperature for this type of fish. To prevent secondary infection (when dark spots on the skin have already appeared), the fish are given a bath with an antiseptic.
Overheating of the water in the aquarium is much less common. If the fish suddenly began to rush up and down and try to jump out of the water, be sure to look at the thermometer! Perhaps the thermostat is out of order, and you risk getting an ear in the aquarium. Most aquarium fish can tolerate temperatures up to 35 ° C, but you shouldn't risk it: each species has its own favorite water temperature.
When choosing fish for an aquarium, observe their division into warm water and cold water. For warm water in an aquarium, a heater with a thermostat is needed.
Chlorinated water disrupts the biological balance in the aquarium, leads to the death of beneficial microorganisms and can be the cause of the death of fish.
If fish are accidentally placed in unsettled water, their gills will turn white. Transplant them into old water and everything will be fine.
If water is urgently needed, and it has not yet settled for at least one (preferably three) days, warm it up at a temperature of 40-90 ° C, cool it and only then use it.
In aquariums with too bright lighting and an abundance of plants , a shift in pH to the alkaline side may occur (in practice, this situation is more often created when experimenting with the composition of water without precise control - alkalization "by eye", etc.). Spreading fins and damaged gills of fish, dullness of integuments serve as an alarm signal. Transfer the fish to settled fresh water and check the pH in the aquarium.
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If fish start to spawn in soft water with a low pH and jerk, rush and try to jump out of the water, immediately return them to their original aquarium and check the pH - have you overdone it, creating an acidic environment? It is not advised to use rainwater to stimulate spawning. In our time, one can no longer be sure of its composition and the absence of harmful substances.
When populating an aquarium with several species of fish, which require different conditions of detention, the interests of one species will inevitably be infringed. If you plant fish that need water with a neutral reaction in an aquarium with an acidic environment, they become lethargic, but shy, their gills periodically shrink convulsively. Without waiting for death, create the required conditions for each species. Be careful when selecting a fish community!