5 Reasons why Guppies Swimming Weird and How To React

Wondering, Why do guppies swim erratically? Why are Guppies swimming upside down? Why are Guppies Swimming Weird? Here in this article, I will answer all the questions: why do guppies swim vertically?

Many people are out there worried about their guppies swimming weird and being unsure about the actual cause. In this article, I will also highlight why my Guppy is swimming sideways. 

We will discuss what things you should do first & fix when you notice your guppies swimming weird. Catching our pet struggling so much to stay afloat is very concerning. 

Fortunately, you are in the right place to get all the answers you need on their weird swimming behavior. Let’s first learn why my Guppy swims sideways.

Article Contents

Why Is My Guppy Swimming Sideways

why is my guppy swimming sideways
why is my guppy swimming sideways?

Guppies that swim sideways usually exhibit the symptoms of a swim bladder disorder. Besides swimming sideways, guppies also sink and lay at the tank bottom or float at the top of the tank. These are all basic symptoms of a swim bladder disorder or disease. 

If your Guppy is struggling to maintain its usual position it could be due to a swim bladder disorder. Here is what you should do first if your Guppy is swimming sideways.

What To Do If My Guppy Is Swimming Sideways?

Stop Feeding Too Much. 

It is an excellent idea to offer a small amount of food for the next 3-4 days. If if the food is complex, consider softening it first.

Try Adding Medicine Called Malafix. 

It is one of the most extensively used remedies for treating fish with disorders and infections. I would highly recommend you add this in their tank every day for about a week to treat your Guppy’s disease. 

It is excellent at treating damages done to the tail and fin. Here, you can learn about if Guppy fish fin or tail regrows.

Raise The Temperature. 

It is always recommended to adjust the temperature slightly to help your guppies recover. It is recommended to raise the temperature to 82 degrees. Giving the temperature constant to 82° around will speed up your Guppy’s digestion process.

Add clean water and conditioner. It is always recommended to add some clean water and some conditioner a little bit. Do a quick water change if you can but if they are struggling too much, then avoid it. 

Avoid changing your water because it can even kill them. If you change the water completely, the chlorine present inside it will ultimately kill them. 

Plus, the other chemical imbalance will also kill other healthy guppies. Clean the water and create a condition that suits their need to recover.

Clean Uneaten And Excess Food. 

If your guppies are swimming sideways, it is always recommended to clean the excess amount of food & uneaten food quickly. 

Any eaten food or excess food always falls to the bottom of the aquarium. If you stir up the gravel and there is cloudiness arising, it’s alarming. You don’t want a guppy that is swimming sideways and continuously snacking on that as well.

Add Aquarium Salt. 

It is always recommended to add at least 1 tsp for 5-gallon water of aquarium salt to help reduce stress on the fish, and it’s weird swimming.

Why Is My Guppy Swimming Vertically? 

If the guppies are swimming vertically, it can be due to overeating. Other than that, a fish that has developed bladder issues will also swim vertically. In most cases, weird swimming behavior like vertical ones in guppies results in death. 

If the above remedies listed above don’t work, consider waiting a bit and monitor. If they’re struggling a lot and bumping with the tank, it’s better to euthanize them. 

When a guppy suffers from swim bladder disease, it becomes impossible to regulate air going in and out. 

So in an attempt to regulate air properly, the Guppy can start swimming upside down or sideways. If your fish is swimming vertically, I recommend you discuss the cause and the treatment with your veterinarian.

Why Is My Pregnant Guppy Swimming Vertically?

Pregnant Guppies mostly start swimming vertically due to overeating. Swim bladder can also be the result of vertical swimming behavior in fishes.  

Why Is My Guppy Swimming In Circles

A guppy can start swimming in a circle due to ammonia poisoning. The ammonia level inside that tank should be controlled. 0% ammonia level is best for their thriving. Let’s learn what it means when guppies swim in circles.

What Does It Mean When Guppies Swim In Circles?

When a guppies start swimming in circles, it usually indicates the elevated levels of nitrites and e ammonia inside the tank. 

Ammonia poisoning can be the result of nitrate, nitrite, and ammonia amount.

It is essential to treat the water and change it immediately. 

You should always perform a small but frequent water change while using a good air pump. Here you can learn if guppies need air pumps or not. 

The air pump will help keep the oxygen level spikes high. You should constantly check the water ammonia level and buildup. It should be near 0 PPM for nitrites, nitrates, and ammonia. 

Let’s learn why my guppies are swimming around like crazy.

Why Is My Guppy Swimming Around Like Crazy?

When a Guppy starts swimming around like crazy, it is often due to the high concentration of ammonia or swim bladder ailment. A fish can start swimming crazy if they are being nipped or chased by a large fish.

Fish Swimming Erratically After Water Change

Again, fish swimming erratically means poor water quality. Any guppy swimming in a circle or similar pattern can be the result of many causes. 

If you notice any pattern in your guppies swimming, it could indicate poor water quality in your aquarium. 

Incorrect PHP level, high amounts of nitrites and nitrates, wrong temperature, ammonia buildup, a sudden large part of water change, and sudden temperature change can result in guppies swimming erratically. 

It is always recommended to do a regular water test. Testing your water more frequently is always a good habit.

Why Do Guppies Swim Up And Down?

why do guppies swim up and down
why do guppies swim up and down?

As stated earlier, guppies swimming upside down means swim bladder disease. A sack that is filled with gas will often keep the fish in trouble. 

They use the swim bladder to maintain their balance, and without it being healthy, they will lose their ability to support their buoyancy. 

It is not a disease but an underlying symptom that needs to be resolved quickly. It would help if you eliminated all the causes responsible for harming your Guppy’s swim bladder. 

Swim bladder seems to be the male culprit for guppies swimming vertically. 

Let’s learn the reasons and the cause that’s harming guppies’ swim bladder.

7 Triggering Reasons Of Guppies Swimming Weird (Cause Of Swim Bladder Disease) 


An injury in their body or skin can result in swim bladder disease as well. Any physical fight or Confrontation between the tankmates and the guppies can result in severe injuries. 

The bladder tends to be severely exposed during physical Confrontation. The recovery rate and the outcome will depend upon the severity of the Confrontation. If there is any bodily injury responsible for swim bladder symptoms, consider relocating that Guppy. 

It would be best to separate them into other tanks which replicate the primary tank environment. Avoid keeping them in overcrowding space by reducing guppies’ tankmates or the number of fish, including shrimps and snails.

Environmental Changes

Any sudden change in their aquarium environment can result in sudden shock while being a potential threat to their swim bladder. 

Their swimming pattern can get severely affected if they are exposed to any sudden temperature change. Apart from that, sudden water changes may also cause trauma.

Despite a drop in temperature, water change also affects their swimming habits. If your Guppy is swimming weirdly or erratically due to the water change, fix the water solution and condition. 

If the temperature is the main culprit behind a stressed-out guppy, consider gradually raising or lowering it.

Since they rest for faster recovery, removing all kinds of noise sources and distractions may disturb your Guppy’s sleeping period, and the pattern is essential. I would recommend you switch off the light.

Inadequate temperature

If the temperature inside the tank is not ideal for supporting their healthy lifestyle, their swim bladder can get severely affected.

When the temperature is low inside the aquarium, their digestive process becomes very slow, enlarging the gastrointestinal tract. This also exerts pressure on their swim bladder, resulting in deformation. 

If a Guppy intestinal tract causes swimming issues or disorders, consider raising the temperature to around 80 degrees Fahrenheit. Adding to that, you should consider adding some salt as well. 

Suppose there are no positive results in every scenario or everything you do, then consider euthanizing it. Some guppy’s swim bladder disease tends to be too extreme to treat. 

In guppies, common fat deposits that the liver accumulates in the s swim bladder are also a deadly threat.

Virus And Infections. 

There are lots of parasites & worms that can be a concern for guppies’ health. Any large concentrated mass of worms inside the puppy’s stomach can create instability. This kind of instability often causes issues in their swimming behavior. 

Their swim bladder can also get severely affected due to bacteria and worms. Bacterias can easily compromise the function of the Guppy’s swim bladder. 

A Guppy with infection usually floats and exhibits weird swimming behavior symptoms when it is seriously sick. Besides swimming vertically, sedentary behavior, white spots, rotten fin, and discoloration mean the final stage. 

However, you can still treat parasites in your guppies by consulting a veterinarian by applying the proper medical treatment and solution. 

If you find a guppy suffering from bacterial infection, seek professional medical help. Any guppy beginning to change its color needs medical support.

Genetic Fault.

Unfortunately, their swimming habits can be severely get affected due to genetics. Some guppies are born with genetic anomalies, which results in their swim bladder being deformed right from birth.

This often happens due to inbreeding. No one can help a Guppy whose swim bladder is naturally deformed. This can only be prevented by avoiding inbreeding or breeding affected offspring. 

If any Guppy exhibits such a symptom, then consider isolating it from the main community fish tank.


Wrapping Up: Whether a Guppy is swimming vertically, horizontally, or staying at the top of the tank, any irregularity in the swimming behavior is a symptom of swim bladder disease, poor water quality, and sudden environmental change. 

Finding the root cause behind guppies swimming vertically or erratically will help them in fixing it. If the Guppy fish is swimming abnormally due to swim bladder disease, consider isolating it first. 

I tried my best to give you all the information needed on guppy swimming behavior. If you find this post helpful, then consider sharing this one with others to help their guppies as well. Check other valuable guppy resources on our website here too.

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