Home Problems & Solutions Fish Jumps out of Tank (Why & How-to Fix)

Fish Jumps out of Tank (Why & How-to Fix)

by gvald

Does your fish have a tendency to jump out of the water of its aquarium? You have found it dying on the ground several times? This is not normal. Here are the different reasons that can explain such behavior. 


Why does your fish jump out of its tank?

1. The water quality is bad

If the water quality in your aquarium is poor, your fish may jump out of it to find a more suitable environment. It’s a matter of survival, in short.


For example, if the water temperature is too hot or too cold, if ammonia levels are too high or if the pH level is inappropriate, a fish will jump out of the tank.


Also, water that is dirty, overcrowded or has too much algae will inevitably lead to a lack of oxygen. If the fish cannot breathe properly, it will look for oxygen elsewhere. For this reason, be sure to change the water regularly, check that the filter is working properly and keep the water as clean as possible.


2. The aquarium is too small

Contrary to what you might think, fish, including goldfish, cannot live in a jar. In fact, they need a rectangular aquarium with at least 100 liters of water per fish. This is the minimum for them to thrive properly. Otherwise, they might actually tend to look for bigger spaces elsewhere…


Thus, it is strongly advised against overcrowding an aquarium. Indeed, fish sometimes need to isolate themselves. However, the lack of hiding places and space can make them feel the need to escape.


Moreover, the more fish there are in an aquarium, the greater the risk that the relationship between them is not at its best. Indeed, it is not uncommon for fish to feel threatened by more aggressive or larger fish. In this case, the smaller fish may try to escape to a safer place.


3. It is a jumping fish

Some fish are known to be great jumpers. These include koi carp, hatchet fish, butterfly fish, comet goldfish, fighter fish and killi fish.


In the wild, these fish jump out of the water to hunt insects, to change water bodies or to escape from danger. This is a natural behavior for them.


To avoid this type of behavior in your aquarium, consider adding accessories, such as floating plants. Filling the aquarium with decorations will prevent your fish from speeding up to propel themselves out of the water. Alternatively, an aquarium with a vented lid can also be a good option.


4. He’s stressed

When you introduce a fish to a new environment, it may start to panic and its first instinct is to escape. Indeed, fish also feel complex emotions and can be subject to stress!


Some situations are more stressful than others for fish. For example, bright lights or sudden flashes can scare them. So, make sure to install hiding places in your aquarium so that your little protégés can take refuge in case of panic.



To conclude, if it is not a jumping fish, it is likely that it does not feel comfortable in its aquarium. The problem may be due to poor water quality, a too small aquarium, or simply that the fish is too stressed.

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