The most common reason why a fish may try to jump out of its home is if the water is in an extreme: too dirty, too warm, too cold, too alkaline, too acidic or too low in oxygen.
Constant – but not excessive – water changes and cleaning the tank will help with these problems, and watch your goldfish for any indications that it may be uncomfortable.
Through the use of a water pump, aerator or air stone and in addition to constant water changes, ensure that the water is well oxygenated and clean.
Goldfish are cold, freshwater fish; they need clean water in a range of 65 to 75 degrees for maximum comfort.
Water that is too warm not only stresses the goldfish, but also prompts them to seek cooler climates elsewhere, even if these are outside the tank.
Furthermore, when the pH of the water falls below 5, or rises above 8.5, your fish is at risk of pain, illness and possibly death.
This acidity or alkalinity of the water can cause severe burns to the fins and gills and cause goldfish to do anything to get relief, including jumping from the tank.
Why goldfishes jump out of water
Your goldfish may jump out of the tank for a number of reasons.
For the goldfish care owner, few attractions are more alarming than fish that are out of the aquarium fish tank, breathless or dead.
Your goldfish may jump out of your tank for a variety of reasons. It is rarely possible to determine exactly why this apparently suicidal act occurred.
However, you can take a number of precautions to keep your aquarium fish safe and happy in your home.
Water temperature
Goldfish do best in water with temperatures between 65 and 75 degrees.
When the water temperature rises, goldfish become more active.
If the water is too warm, your goldfish may accidentally jump out of the tank due to increased activity, or an instinctive attempt to reduce their body temperature.
Try to use the aquarium’s self-heater and maintain a constant water temperature, and avoid placing the tank in direct sunlight or near heat sources.
Water quality
A tank with dirty water is unlikely to contain enough oxygen for goldfish to thrive and has enough ammonia waste present to become harmful to the fish.
Poor water quality can cause a fish to jump from a tank in an attempt to survive.
The site recommends changing about a third of the aquarium water once a week.
Further steps that can be taken to maintain water quality include installation and maintenance.
A suitable filter and making sure the tank is large enough for its inhabitants.
Behaviour
During the life of your goldfish, certain events and situations may occur that could increase your chances of jumping.
For example, until a goldfish settles into a new environment, stress or emotions may cause it to jump from a tank.
You also have a certain risk of losing a goldfish during breeding. When excited males chase females around the tank.
This frenetic activity can cause a goldfish to involuntarily jump out of the water.
Health
A goldfish experiencing discomfort due to infestation or other parasitic disorder may swim around the tank more erratically than usual.
The fish’s movements may be more uncontrolled, jerky or frenzied.
The more likely it is that the goldfish will involuntarily jump out of the water.
Observe the fish regularly for any changes in behaviour or appearance and refer any concerns to an aquatic expert or veterinarian.
How to stop goldfishes from jumping out of the pond
If you notice that your fish are jumping out of the pond or bowls, it is a sign that you need to act immediately.
The first thing to do is to start a big water change and simultaneously test the water for ammonia, nitrates, nitrites and temperature.
These are the most common culprits of mistakes that cause a goldfish to jump out.
If you have a quarantine tank, then move your fish to this tank.
This will save you from losing all of your aquatic life if something truly terrible happens in your pond or main aquarium.
Make sure that your pond and tank receive sufficient oxygenation and agitation.
If the tests come back negative for problems, then you need to start looking around the area to see if any contamination may have entered the pond.
If your pond is in an area where pesticides, herbicides or fertilisers are used, this could be the problem.
Test the water to see if there are any traces of these chemicals in the water.
Make a visual check of the surrounding area. Are there any leaks or cracks in the edges of your pond? Is there a new water system nearby that has changed the water flow?
If you have used new medication in the pond or aquarium, this could be the cause even if you have used the correct dosage.
If you suspect that the medication is the cause, a couple of large water changes to dilute the medication may be sufficient.
Otherwise, contact the supplier and ask them what to do if this happens.
Usually, there is a specific technique they can give you to detoxify the fish before returning them to their pond or aquarium.
Also, consider adding a carbon filter to suck up any remaining medication.
