FTC GUIDELINES PLEASE NOTE: we act as an affiliate for several companies that feature on our website. In some cases we may earn a commission from referrals to those companies. For further information please refer to our Privacy page.

Why Do Tropical Fish Swim on their side?

What would happen if one day, while you were watching your beloved tropical fish swim around in their aquarium, they suddenly stopped moving and just floated to the top of the water?

If you’ve never experienced this phenomenon with your own fish, consider yourself lucky! But chances are, you may know someone who has, and that’s why you’re reading this webpage now – you want to learn how to help treat swim bladder disease in tropical fish.

Read on to learn more about the causes and symptoms of swim bladder disease in fish, and what you can do about it!

Get Your Free Report Today -

Top 3 Mistakes Newbies Make Setting Up Their Fish Tank.


Goldfish with swim bladder diseaseGoldfish with swim bladder disease
Humanfeather / Michelle Jo, CC BY 3.0, via Wikimedia Commons

What is swim bladder Disease

While there are multiple causes of swim bladder disease, it is important to note that you cannot fully treat or prevent swim bladder disease unless you know what caused it.

There are many things that can cause a tropical fish to swim on its side including parasites, bacterial infections, poor water quality, constipation and food additives.

While each of these factors must be treated individually and specifically if they were causing your pet’s symptoms, your pet may only respond well to certain medications.

Your veterinarian will be able to discuss with you how best to proceed in such a case based on your pet’s diagnosis.

Swim Bladder Disease Symptoms

Several things can go wrong with a fish’s swim bladder, causing it to deflate or lose its ability to function.

Often caused by bacterial infections, internal parasites and diet problems can lead to swim bladder disease in many freshwater species of ornamental fish.

The symptoms of swim bladder disease include one or more floating at an odd angle when stationary, swimming at an odd angle when moving through the water, and its buoyancy will shift as the fish breathe, making them prone to turn upside-down.

Treating Swim Bladder Disease

The swim bladder is an internal organ that helps keep a fish’s body buoyant and is filled with either gas or fluid.

When a goldfish or other tropical fish has swim bladder disease, there is an imbalance between gas and fluid in its swim bladder.

Unlike when humans are ill and have gas, in many cases, there is too much gas inside a diseased goldfish’s body.

Treatment involves adding salt to your aquarium water and feeding your goldfish high-protein foods such as brine shrimp to encourage more burping and more natural release of built-up gases—more than likely resulting in your sick goldfish swimming right-side-up again!

diet and Nutrition

It's best to keep control of the diet of your fish, specifically if the fish eats too much, therefore causing the swim bladder issues.

Normally, you should not feed the fish for two to three days or feed sparingly 1-2 times a day (small amounts of fish food). The rule of thumb is that if the food is left uneaten after a few minutes, take the uneaten food out of the aquarium.

Removing the fish from the fish tank and place in a quarantine fish tank is the next best option. If the symptoms still persist after three days of fasting, try out other treatment options, including raising the water temperature between 78 and 82 Fahrenheit.

Swimming Tips For Fish With Swim Bladder Disease

Once your tropical fish is diagnosed with swim bladder disease, there are several things you can do to treat it. First and foremost, they need to stop swimming sideways or upside down.

Here are some simple solutions: Make sure your tank water is between 78 and 82 degrees Fahrenheit; goldfish prefer cooler water, while other types of tropical fish prefer warmer temperatures.

The warmth in a pet store can also upset stomachs and make them swim sideways. Adding aquarium salt, which keeps tanks healthier overall, will also help stabilize your fish's diet and aid with digestion.

How to prevent swim bladder disease

Some of the most common symptoms of swim bladder disease include a loss of equilibrium and an inability to maintain a vertical position. If your fish is swimming with his nose in one direction, either up or down, and his gills are not facing toward you as they should be, he may have swim bladder disease.

If your aquarium is stocked with more than one type of tropical fish it's important to establish which species are affected first so that you can treat them accordingly.

Some species respond differently to treatment and some species may not recover from swim bladder disease at all, so knowing exactly what type(s) of aquarium inhabitants need immediate medical attention is key for getting your aquatic friend healthy again.


When you own a freshwater aquarium, you take pride in your hobby and its beauty.

You want to provide a safe, healthy environment for all of your beautiful fish. That’s why keeping an eye out for symptoms of swim bladder disease is so important.

Swim bladder disease can be hard to spot at first, but when you know what to look for (and how best to help your sick pet), it can easily be prevented using the methods listed above and by treatment with medication.