How and why remove dead fish from the aquarium
Dead fish should be removed from the aquarium as soon as possible:
- The water quality is affected by the decomposition.
- Dead fish quickly become moldy.
- The other fish eat dead fish and can thus take over pathogens.
- Some pathogens leave the infected fish when their host dies and look for new victims.
The body of a freshly dead fish contains gases, for example in the swim bladder. Depending on how much gas the fish has in total and how heavy the fish is, it sinks or rises to the water surface.
If the lift from the gas is greater than the downforce from its own weight, the dead fish will rise to the surface. Otherwise he will sink to the ground.
A dead fish floating on the surface can easily be removed from the aquarium with a net.
In a dead fish that has sunk to the bottom, further gases are produced by decomposition, so that after a while the fish also rises to the surface of the water. Because the decomposition can produce pollutants such as nitrite, it is best not to wait until the fish has come up before removing it.
Large aquariums can certainly cope with a small fish rotting in them. In small aquariums or with large fish, the water quality can deteriorate significantly.