Unbeknown to some, fish jump out of water. Unfortunately, as the owners aren’t always around, the fish suffocate and die once they hit the ground. Many novice fish keepers lose a few of their community in this way due to the tank’s conditions not being quite right.
Jumping is a defense mechanism against predators and poor conditions. Fish will jump out of their tank if it doesn’t contain enough dissolved oxygen. Similarly, they’ll also try to escape if there is too much ammonia and nitrites in the water. Other causes include an insufficient sleep cycle, lack of tank space, parasites, diseases, and a lack of hiding spots. For some fish, jumping is a natural instinct.
To prevent fish from jumping out of their aquarium, you’ll need to improve the tank’s conditions. Luckily, there are several measures you can take to do this, which should create a happy, harmonious home for your fish.
How Do Fish Leap Out Of The Water?
All fish do is swim and float, right? Surprisingly, that’s not true. Fish can leap several inches into the air, jumping straight out of the water.
To do this, they bend backward over their tail, forming a C-shape. They then flick themselves forward while at the same time paddling with their fins as quickly as they can.
This creates an up and down wave-like motion throughout the fish’s body (undulation), launching the fish through the water’s surface into a long arch, causing them to land outside the tank.
This impressive jumping technique allows fish to leap from a fixed position.
How High Can Fish Leap?
If you’re wondering how high can fish jump, the answer isn’t a simple one, unfortunately. Most aquarium fish can jump a couple of inches into the air – just enough to fall out of the tank. For example, betta fish can leap between 2-3 inches into the air.
That being said, some species, like the hatchetfish, can jump as high as 5 feet into the air, making them one of the most accomplished aquatic jumpers.
Similarly, some fish can jump out of the smallest gaps. If your tank has a gap that a coin can fit through, small fish can, too.
Why Did My Fish Jump Out Of The Tank?
Fish jumping out of water isn’t normal. However, when they jump, they do it with purpose. In most cases, fish leap out of their tank to seek a different body of water. There are several reasons why they do this, but it’s almost always the sign of an aquarium issue.
Unfortunately, there’s rarely any water for fish to jump into in captivity, meaning they hit the floor and suffocate to death.
To prevent this and improve your fish’s conditions, you must understand the reasons for their behavior, which includes:
Poor Water Quality
Fish hate living in dirty water. Not just because it’s unpleasant, but poor water quality can also poison them. If your tank has elevated ammonia and nitrite levels, it’ll cause your fish to leap out of it in search of a better home. Sadly, this is an act of desperation.
If your fish start leaping out of the tank, immediately check the water for ammonia and nitrite. If the levels are too high, you must quickly clean the water to save your fish. Signs of ammonia in fish tanks include:
- Foul odor
- Fish gasping at the tank’s surface
- Lethargy
- Loss of appetite
- Red or cloudy eyes
- Redness around the gills
Thankfully, once you know that harmful ammonia’s in the tank, it’s easy to remove. The difficulty is acting quick enough to prevent your fish from suffering long-term damage. Ammonia poisoning is impossible to cure, and side-effects include:
- Infections
- Blindness
- Recurring sores
- Compromised immune system
- Difficulty breathing
- Torn fins
As you can see, fish prefer to take their chances out of the tank than suffer these painful symptoms.
Low Oxygen Levels
Fish will jump out of their tank if there’s a lack of dissolved oxygen in the water. While it’s difficult to tell when oxygen levels are low, it’s caused by:
- Stress
- Poor water quality
- Lack of aeration
- Too many fish
- Algae buildup
Fish don’t have lungs, so they need lots of dissolved oxygen to breathe. As described by the U.S Geological Survey, fish consume dissolved oxygen through their fills.
If they’re unable to do this, they’ll leap out of the water to find a source of water with more dissolved oxygen, not realizing that this doesn’t exist. Signs of low oxygen levels include:
- Gasping for air at the tank’s surface
- Low energy, causing fish to stop swimming or moving
- Imbalanced or uncoordinated swimming
- Loss of appetite
- Labored breathing
- Rapid gill movement
Fish only jump out of the water in the most extreme circumstances, so you must add more dissolved oxygen in your tank to prevent your fish from suffocating or leaping to their deaths.
However, bear in mind that it’s also possible to add too much oxygen to your tank, which can also be harmful to your fish’s health. As a result, fish that live in oxygen-saturated water develop gas bubble disease, which causes a slow and painful death.
Poor Sleep Cycle
Scientists believe that most fish sleep in similar sleeping cycles to us. Most fish species are diurnal, which means they’re active during the day and sleep at night.
If these conditions aren’t emulated in captivity, they become restless and frustrated. A lack of sleep also causes them to become stressed and forces them to leap out of their tank.
All tanks need a period of darkness, so turning off the light at night and keeping the tank illuminated during the day allows your fish to conserve their energy.
According to the National Ocean Service, fish “sleep” by reducing their activity and metabolism. They also remain alert to danger, floating in place or wedging themselves into the substrate.
Avoiding Prey
As described by a research journal on PLoS One, some fish jump out of their tank to avoid predators. When smaller prey fish share a tank with larger predator fish, they aim to confuse the predator fish by leaping out of the water.
The journal also found that wild guppies, which were the subject of the researcher’s studies, use their jumping ability to spread their species into new habitats to avoid predators. This is an essential part of their evolution.
While jumping is an effective method for fish wanting to avoid becoming lunch, captive fish that live inside an aquarium don’t have the brain capacity to understand that there isn’t another body of water nearby.
As a result, they end up landing on the cold ground. If their owner isn’t nearby to put them back into the aquarium, they suffocate.
Similarly, some fish jump out of their tank to catch flies and other insects that buzz around the aquarium. This includes species that feast on insects, including:
- Blackskirt tetras
- Jack Dempsey fish
- Tiger barb
- Betta fish
- Angelfish
Maintaining a regular feeding schedule and ensuring your fish have plenty to eat can help prevent this. Though, for some fish, their instincts are too strong.
Lack Of Room
Fish need room to swim and grow. If they don’t, they become ill and depressed. They also develop several behavioral problems resulting from their environment. Fish that are in overcrowded or tiny tanks are at risk of:
- Stunted growth
- Aggressive tankmates
- Stress
- Ammonia poisoning
- Reduced oxygen levels
- Fatty liver disease
These conditions are not conducive to a happy home, so fish will attempt an escape by jumping out of their tank in search of somewhere better. You’ll know if your tank is too small because the fish inside it:
- Lack the appropriate swimming space
- Lose their appetite
- Develop a range of diseases
- Become depressed
The only way to prevent your fish from making a getaway is to improve the conditions and provide a larger, roomier tank. This should reduce your fish’s stress levels and make them feel more comfortable.
Parasites And Diseases
When fish are in pain because of diseases or parasites, they’ll jump out of the tank. Sometimes, the friction of jumping out of the water relieves their itchy skin for a short moment.
Many diseases remain undetected until it’s too late. That’s why you must look out for signs of pain and distress while keeping your tank clean to prevent harmful bacteria from building up and infecting your fish.
Lack of Hiding Spaces
Similar to a lack of room, fish swim in and out of plants and decorative features as a form of mental stimulation and enrichment. Shy fish also use them to hide from larger, dominant fish, protecting themselves from danger.
Without enough hiding spaces, some fish feel threatened and vulnerable. They’ll also become stressed, which will make fish physically unwell. As a result, they’ll flee the tank in an attempt to find somewhere better to live.
Natural Behavior
For some fish species, like the betta fish, jumping is natural to them. Many fish live in puddles and swamps, which dry up in the summer months. As a result, fish have no choice but to take a leap of faith, jumping out of the small body of water they’re in in the hopes of reaching a bigger one.
Lucky fish jump into larger puddles. However, all’s not lost if they miss water completely, as they breathe through an organ called the labyrinth. This allows them to breathe for a longer period, giving them a better chance of finding water. Labyrinth fish include:
- Betta
- Blue gourami
- Chocolate gourami
- Croaking gourami
- Dwarf gourami
- Giant gourami
- Honey gourami
- Kissing gourami
- Moonlight gourami
- Paradise fish
- Pearl gourami
- Powder blue gourami
- Snakeskin gourami
- Sparkling gourami
- Three-spot gourami
Some fish retain these jumping instincts, even in captivity. While you can’t stop this behavior completely, you can prevent it by emulating their wild conditions as much as you can.
How To Stop Fish Jumping Out Of Tank
Seeing as you won’t be around all the time to put your fish back into the tank if they jump out, you’ll need to prevent them from doing so. Otherwise, the fish are at risk of a slow and painful death.
Similarly, if your fish are jumping out of the tank, it’s because something in their environment isn’t right. As a result, they’re unhappy and uncomfortable. To protect your fish, follow these steps:
Cover The Top
The most obvious way to prevent your fish from getting out of their tank is to place a cover over it. Some already come with a hood, but others don’t. If you don’t have one, it’s worth investing in one to protect your fish.
Glass lids are more durable and practical than other types of covers. They’re also easier to clean and are more effective at preventing evaporation. However, plastic covers are also good if you’re on a budget.
Not only can a cover prevent fish from jumping out of the tank, but it prevents items from falling in.
Maintain Tank Hygiene
To keep your aquarium safe from harmful ammonia and nitrites, you’ll need to clean it, carrying out a bi-weekly water change.
When you do, replace between 10 to 20% of the tank’s volume with fresh water. Then, follow these steps:
- Dechlorinate the water and scrub the tank’s sides to remove algae and bacteria.
- Siphon out all waste that has settled on the substrate to prevent it from decomposing and raising ammonia levels.
- Clean out the filter, swooshing it in the tank’s water. Don’t run it under a faucet, as you’ll remove all the beneficial bacteria.
By doing this every other week, you’ll prevent harmful ammonia and nitrite levels from rising, creating a healthy environment for your fish to live in. As a result, your fish won’t be as inclined to jump out of their tank.
Choose Compatible Tankmates
To prevent fish from jumping out of the tank because of aggressive or predatory fish, choose wisely before stocking your aquarium, being careful to build a collection of community fish that are likely to live in harmony with each other.
To do this, you’ll need to research your favorite fish to see if they’re compatible with tankmates. Wherever possible, gather fish from the same region, as they’ll be able to communicate with each other in similar ways. For example, angelfish get on well with:
- Larger tetras
- Rainbowfish
- Gourami
- Corydoras
- Larger rasboras
- Catfish
- Mollies
- Plecos
In contrast, some fish species don’t do well living with closely related species. Before making a purchase, seek advice from a fish breeder, who can guide you on which fish go well together.
Choose A Bigger Tank
We’ve already highlighted the dangers of having a tank that’s too small. If you notice the signs we’ve mentioned, then you’ll need to invest in a bigger tank to prevent fish from attempting to jump out of it to escape the cramped conditions. There are three popular methods for measuring the correct tank size, which are:
- The one inch per gallon rule
- The two inches per gallon rule
- The aquarium’s floor and surface area calculation
The size you ultimately choose depends on the number of fish you have, along with their shape and size.
Some fish also prefer wider tanks, so you’ll need to do your research on what yours will be most comfortable living in.
Alternatively, if you don’t have room for a larger tank, you could remove some of the fish you already have into a separate aquarium. You could also sell them to a reputable person.
Add Plants And Ornaments
Offer your fish hiding spaces from other fish by adding plenty of plants and decorative features that they can swim amongst. This will provide your fish with mental stimulation and allow them to hide whenever they feel vulnerable.
As a result, they should feel less inclined to get away by jumping out of their tank.
Limit Noise
Sound travels ten times faster in water than in air. As a result, loud, constant noise disturbs fish, making them stressed and uncomfortable. To get away from the noise, they’ll leap out of the tank.
To prevent this, place your fish in a quiet room that offers your fish some peace. Turn off all electricals, such as the TV and radio, when they’re not in use.
Increase Oxygen Levels
As already mentioned, low oxygen levels force fish to leap out of the tank in search of better conditions. As a result, to increase your aquarium’s oxygen levels:
- Add plants.
- Provide good-quality substrate, such as fine gravel, small stones, or sand.
- Buy a tank with a bigger surface area.
- Increase surface agitation using a surface bubbler, HOB filter, powerhead, wavemaker, or spray bar and sprinkler.
Similarly, make sure the tank isn’t overstocked, as this will rapidly deplete the oxygen supply.
Aquarium Fish That Don’t Jump
Unfortunately, all fish can jump out of their tank and will do so if their conditions are bad enough. As described by some fish owners, only dead fish don’t jump.
As a result, you’ll need to do everything you can to prevent this, keeping your fish safe. This is especially important if you’re not always around to put your fish back in the tank.
Losing fish by them jumping out of their tank isn’t pleasant. It’s also hard not to take the situation personally. However, you must keep a close eye on your tank’s conditions to ensure there are no problems. If you notice your fish displaying signs of discomfort, look for stress and illness symptoms before your fish get a chance to escape.
