Why Is My Guppy Moving Up And Down?

Fishes show many behaviors that tell us how they are feeling, of which one is moving up and down. So, why is my guppy moving up and down? Let us find out.

Swim bladder disorder is the cause of guppy moving up and down. However, there can be other reasons behind guppy moving up and down, like sudden environmental changes, injury, water condition, and inappropriate feeding. Providing adequate water conditions and diet care will help your guppy to recover.

We will try to understand why your guppy moves up and down and how to solve that issue. Also, there are some actions you can take to prevent your guppy from coming into this state in the first place. So, let’s get into it and find the answers to all of your questions. 

Why is my guppy swimming up and down?

Swimming up and down is not something usual for guppies as they don’t usually swim in this manner, though it is normal for other fish like shrimp. A swim bladder disease can probably be the reason behind guppy swimming up and down. 

The swim bladder, also called the air bladder, contains gas and functions as a hydrostatic organ, helps fish to maintain their depth without floating upward and sinking. Any harm to the swim bladder will make it difficult for your guppy to swim.

Detecting that your guppy is suffering from a swim bladder disease will not help you know how to solve the issue, as it is not a disease. It is a symptom. You can help your guppy suffering from swim bladder disease by detecting the cause of swim bladder disease and try to fix it.

There are more reasons behind guppy moving up and down apart from the swim bladder disease:

Inadequate water temperature

The water temperature plays a very vital role in guppies’ health. Water with a low temperature can slow down your guppy’s digestive process, which will increase the gestational tract. This can apply pressure on the swim bladder resulting in deforming the swim bladder. 

An owner should make sure to raise the temperature of the water (70-80) degrees Fahrenheit if an enlarged stomach is the cause of swim bladder disease.

More organs can harm the swim bladder once being enlarged, like a kidney with cysts or liver can gather fat deposits that can harm the swim bladder. 

Genetic defects

Some fishes are born with abnormalities which means that there is a possibility that your guppies swim bladder is deformed from birth. Most such cases are found in a fish who has come to the world by couple inbreeding.

An owner can do nothing if a genetic defect is a reason behind their guppy moving up and down. In such cases, euthanasia is the only option left for an owner as there is no such treatment or alternative to fix this problem. 

An owner should make sure to place the guppy with such genetic defect in another tank to avoid defect offspring by any further breeding. 

There are rare cases of fish born with genetic defects that affect the swim bladder, but you will usually detect the symptoms at an early age of your guppy. 

Inappropriate food

If you provide your guppy food that is no longer fresh and pleasant to eat, this will produce a lot of gas in their gut, making your guppy overly buoyant as the gas will enter their swim bladder. 

There can be the same result by gulping air as guppy will eat food from the water’s surface. Overfeeding and constipation can also be the reason behind it. 

Make sure not to feed your guppy for three days in such a case; after three days, feed them skinned and cooked peas. Doing this will help your guppy to come over from constipation. You should anyway consider this treatment if your guppy is moving up and down. 


The swim bladder can be injured when there is a physical conflict between guppies and their other tankmates. The possibility of recovery will completely depend on the damage caused by physical confrontation.

An owner should make sure not to expose their injured guppy to angry tankmates before they recover fully by placing the injured guppy in a separate tank where they can recover. 

An owner should avoid overcrowding their guppies tank by placing some of the fish in another tank. For example, you can use a rule of one inch per gallon of water, which means if your guppy is 2cm long, you should provide a 2-gallon tank to your guppy, and in the same way, two guppies will require a 4-gallon tank and so on. 

Environmental changes

Your guppy can suffer from a shock if you do a sudden environmental change around them. Also, it can affect your guppy swimming. Environmental changes include the sudden rise or down of the water temperature. Usually, you will see this in a guppy that is being introduced to a new aquarium. 

The sudden transfer of guppy to one tank from another can make your guppy come under stress, affecting their swimming habits. An owner should remove the elements that have made your guppy coming under stress. 

If there is any issue with the water temperature, then make sure to fix it slowly, as an immediate change of the temperature will make them come under stress. Also, removing everything that can become sources of noise or any other distraction and lowering the light will help you expedite the process of your guppy’s recovery. 


Parasitic worms are not something of which you should concern as they are harmless in ideal conditions. However, a large and concentrated mass of worms present in your guppy stomach will create instability, affecting your guppy’s swimming behavior.

Where parasitic worms are not harmful in ideal conditions, bacterial infection can be so critical that they can affect your guppy swim bladder in a way that it loses function, which weakens the guppy’s ability to swim properly. 

An owner should know that the bacterial infection that makes guppy lose their ability to swim properly is severe as these symptoms only occur when your guppy is seriously sick.

A guppy keeper should detect the infection by seeing other symptoms rather than guppy moving up and down, which can be white spots, sluggish behavior, or rotten fins. In addition, your guppy may begin to change their colors because of the infection. 

Medical support is essentially needed in case of guppy having worms or bacterial infection. Bacterial infection can be treated by antibiotics, whereas parasites can be treated by antihelminthic. Still, an owner should contact a vet to ensure that they are treating their guppy with the proper medication.

Selective breeding errors

An owner making their guppy go through selective breeding for improving their physical ascribe can produce abnormalities. 

In some cases, the guppies at issue are not deformed from the beginning; they are more susceptible to diseases that affect the guppy’s swim bladder, which is also a concern and difficult to treat but not impossible. 

If the cause of the swim bladder disorder is selective breeding, then this is critical for your guppy. Unfortunately, there is no way of treating your guppy to make them less unprotected from the swim bladder disease. 

Suppose your guppy doesn’t have any disorder. In that case, the only thing you can do is prevent the swim bladder disease from demonstrating, which means removing aggressive tankmates from your guppies tank, Feeding appropriate food, and providing your guppy a perfect tank and water conditions.

Ways to prevent your guppy from such problem?

There are some ways to treat guppies that are swimming up and down:

Choose right tankamtes

As discussed above, Physical conflict between the guppy and other tankmates can injure your fish swim bladder. A wise solution to this problem is removing the aggressive tankmate from your guppies tank. Instead, try adding non-aggressive fish to your guppies tank, which will live peacefully with your guppies.

If removing the aggressive fish and replacing them with non-aggressive fish is not an option for you, then you can make a hiding place for your guppies in the tank by adding plants and decorative things inside your guppies tank. 

Adding plants and decorative items in your guppies tank will help them hide whenever your guppies attract the outrage of the aggressive tankmates. If applying this idea doesn’t work, install a divider to separate your guppies from aggressive tankmates.  

Appropriate feeding

Avoid overfeeding your guppy, and also, an owner should make sure to provide fresh and pleasant food to their guppy. Provide your guppy food in a quantity that they can complete within 1-2 minutes after serving.

If you are feeding your guppy dry food, soak them before providing it to your guppy, as it is equally necessary as thawing frozen food before feeding it to your guppy. In addition, experts recommend providing your guppies food that can sink, as it can prevent your guppy from gulping air from the water surface. 

Provide the adequate water condition

Make sure to provide your guppy with an appropriate water condition. Good water conditions will help your guppy to prosper. If your guppy is not getting the adequate water temperature and ph level, it can harm your guppies by weakening their immune system, resulting in illness that can affect the swim bladder. 

Checking the water parameters is essential in case your guppy is not behaving well. These are the condition which an owner has to provide to their guppies:

  1. Water temperature: Guppies like to live in warmer water. An owner should make sure to provide their guppies a water temperature between 70-82 degrees Fahrenheit (22-28 degrees Celcius) 
  2. Water ph level: ph level tells us how acidic and basic the water is. Ph level ranges from 1 to 14, where seven is neutral, less than seven is acidic, and greater than seven is basic. Guppies are very hardy fish and can live in a range of ph levels, which means the best ph level for your guppies will be 7 and 8.
  3. Water hardness: Water hardness refers to the amount of minerals dissolved in the water. Guppies will live comfortably in the water hardness, which varies between 8-12. 

Maintain proper hygiene

An owner should make sure to maintain proper hygiene inside their guppies tank. For maintaining proper hygiene, you should add a filter to your guppies tank. A filter is a key element for your guppies or any other fish tank. 

A filter will help you to clean the water and prevent it from getting toxic. It will extract the solid waste from the water and make it clean for your guppies to live comfortably. 

An owner should also make sure to test the elements nitrites, ammonia, and nitrates. Change the water regularly in case these elements are not concentrated at an ideal level. 

A tank that is not appropriately maintained can be the reason behind your guppy’s illness, which can affect your guppy’s swim bladder. By maintaining a perfect environment of your guppies tank, you keep them away from infections and diseases. 


Place your guppy, affected by genetic deformity, into a separate tank rather than killing them. As discussed above, it will prevent them from breeding with another guppy and producing offspring with the same abnormalities. 

You will detect the symptoms early if there is a case of a genetic defect in your guppy, as the guppy with a genetic defect will show the signs at an early age. 

There can also be some very understandable reasons behind your guppy moving up and down, and these are:

  1. Your guppy is creating a complete motion to make it difficult for their predators to get them.
  2. Your guppy is looking for food.

In case your guppy is healthy and in an appropriate water parameter with good hygiene. If your guppy doesn’t have a swim bladder disorder or any other disease or infection and is living in a perfect water condition, then only you can consider the above understandable reasons. 


Swim bladder disorder can be the primary reason for your guppy moving up and down. Secondary reasons can be an injury, infection, inappropriate feeding, and sudden water changes. There can also be other reasons like they are searching for food or avoiding being stable so that their predators find it difficult to attack them. Providing your guppy with an adequate water parameter and a hygienic water condition will help them be far away from infection and diseases. 

An owner should make sure that they feed their guppy fresh and pleasant good, as feeding guppy bad food will harm their immune system, affecting swim bladder. If your guppy has a genetic defect, place them in a separate tank to prevent them from breeding with other healthy guppy and producing offspring with similar abnormalities. 

Reference: NCBI

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