Why Is Your Guppy Swimming Upside Down? (SBD Explained)

If you catch your fish swimming upside down, don’t panic! It’s not a surefire sign of their demise. One common cause is swim bladder disease, but don’t worry, there are steps you can take to treat it. So, in this article, we’ll talk about Guppy Swim Bladder disease, and everything you need to know about it.

So, keep reading!

Key Takeaways:

  • Guppies swimming upside down might signal Swim Bladder Disease (SBD), a common ailment among fish, often caused by trauma or congenital factors.
  • Observing signs such as clenched fins, distended belly, erratic swimming, and lethargy can indicate SBD.
  • Initial treatment steps involve regulating tank temperature and modifying the guppy’s diet by feeding boiled peas to address potential constipation issues.
  • If initial steps don’t work, an Epsom salt bath can help relax muscles and ease organ issues related to SBD.
  • Consulting a veterinarian is recommended if prior treatments haven’t been effective; suitable products for bacterial infections or parasitic concerns are available.

Guppy Swim Bladder Disease: Signs To Observe

First of all, swim bladder disease is fairly common among fish. Most of the reasons that it occurs have to do with trauma to the fish, either internally or externally. It can also be congenital, meaning they were born with the condition.

Unless you hatched the fish yourself, you will not be able to know whether it was congenital or trauma-based until treatment either works or fails. The best starting procedure, during observation then, is to isolate your fish in an isolation tank.

If you do not have an isolation tank, then isolate them in a small fish net to keep them from breeding with the other fish. Observe for the following:

  • Fins clenched: Most fins will spread to give maximum drive. The lethargy associated with swim bladder disease will cause the fish to conserve energy, including the energy required to spread the tail fin.
  • Distended belly: Often times swim bladder disease will include other organ function but can be caused by digestive problems. Observe the belly of your guppy, which is normally translucent. If it is distended, it will be easier to see through and observe bloating and stored food waste.
  • Erratic swimming. The swim bladder helps your fish in staying in one place with minimal effort. It allows fish to surface and dive at will. When compressed by other issues, it will be lopsided, much like having inner ear problems will cause you to stumble. They may swim sideways, upside down, or even rapidly without seeming to gain any movement.

Treatments for Guppy Swim Bladder Disease

Much like the logical magic of Occam’s razor, made famous in television and movies, it is good to start with the simplest issue and least traumatic treatment.

Treatment Steps for Swim Bladder Disease in Guppies
Check Tank Temperature
Change Diet
Epsom Salt Bath
Consult a Veterinarian

Check the Tank Temperature

 According to Dr. Jessie Sanders only ten percent of cases diagnosed at home as “fish bladder disease” are actually fish bladder disease-related. The first culprit is the temperature of your tank. If it is wildly off, allow the temperature to slowly rise to normal and the issue should fix itself.

Change Their Diet

If the belly is distended, either external shock from bullying or constipation from low-quality food has caused your guppy to stop passing waste, then isolate them and feed them three or four boiled and peeled peas a day until the problem resolves.

Use Epsom Salt

If the diet and temperature have not fixed anything, use an Epsom salt float. Epsom salts have the same effect on guppies as on humans, in relaxing muscles. Often times it will help to ease traumatized organs that have invaded the bladder space and can help constipation problems. These are the steps for the Epsom salt bath.

  • Fill one bucket with one gallon of water that is the same temperature as the tank.
  • Dechlorinate the water.
  • Add one tablespoon of Epsom salt.
  • Add your guppy for fiteen minutes.
  • In a second bucket dechlorinate a gallon of water and add a teaspoon of salts.
  • Allow your guppy fifteen minutes in that treatment.
  • Return them to the tank.

Consult Your Veterinarian

If the prior three steps have not worked, it is likely a bacterial infection and actual swim bladder disease. Consult your veterinarian for their recommendations on products. The best commercially available products are API Melafix for bacteria. If you suspect it may be a parasite related then BettaMax is a better alternative.

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How to Prevent Guppy Swim Bladder Disease

To prevent Guppy Swim Bladder Disease, consider these measures:

  1. Dietary Balance: Ensure a varied, high-quality diet to avert constipation or digestive issues. Combine high-fiber foods like boiled peas and offer nutritionally rich feeds suitable for guppies’ well-being.
  2. Tank Conditions: Regularly check water parameters such as temperature, pH, and ammonia levels. Maintain optimal conditions through periodic water changes and tank cleanliness. Monitor filtration systems and perform routine maintenance.
  3. Space and Environment: Provide adequate space within the tank to allow free movement for guppies. Avoid overcrowding and ensure a well-planted, well-decorated tank that offers both hiding spots and open areas for exploration.
  4. Stress Management: Reduce stressors by avoiding aggressive tank mates and sudden environmental changes. Aim to maintain a stable and consistent environment to ensure the comfort and well-being of guppies.
  5. Observation and Health Monitoring: Regularly observe fish behavior and appearance to detect any early signs of distress, illness, or unusual behavior. Early detection facilitates prompt treatment and avoids potential health deterioration.
  6. Disease Prevention Protocols: Quarantine new fish additions to prevent the introduction of diseases. Implement preventive health measures, like periodic deworming and monitoring for common guppy diseases.

Don’t Give Up and Keep Watching

We don’t build aquariums to add more stress to our lives. That’s what jobs, PTA meetings, and traffic are for. We build these aquatic wonderlands to enjoy the serenity of our fish swimming in the bubbly worlds they occupy.

If your guppy is swimming upside down, there is a 90% chance that you can treat the problem without even leaving your home. In the event it’s an actual sickness, it is still highly treatable.

One final warning from Dr. Sanders is to avoid the popular fish floaties method, whereby fish owners give what amounts to floaties to their fish. These do more harm than good. Be patient and follow the process.

If this fish is part of teaching your kids to be responsible with pets, bring them along. They will benefit massively from learning how to keep their heads clear and the treatment ready.

Check out this video by Guppy Channel on all the reasons your Guppy is swimming weirdly!


Why Is My Fish Upside Down but Still Swimming?

One possible reason for a fish swimming upside down could be swim bladder disorder, which impacts the fish’s buoyancy control. Another possibility is low oxygen levels in the water, causing the fish to adjust its swimming to breathe more easily. It’s best to consult a veterinarian for a proper diagnosis and treatment.


Seeing your guppy upside down may alarm you, but Swim Bladder Disease isn’t necessarily the end of the line. Look for signs, adjust tank temperature, tweak their diet with boiled peas, and consider an Epsom salt bath. And, if needed, consult a vet for tailored advice.

Remember, 90% of the time, home treatments work. Don’t fall for fish ‘floaties.’ Be patient, observe, and treat. Let’s keep our little aquatic companions happily swimming in their serene worlds!”


About the author

Hey there! I'm Antonio, the passionate owner and chief editor of Betta Care Fish Guide. With over half a decade of hands-on experience, I've become your go-to expert for all things betta and tropical fish.

Over the past 5 years, I've not only kept bettas and other tropical fish but also connected with a diverse network of hobbyists, seasoned fishkeepers, and even veterinarians.

Now, I want to help other beginner fish keepers who had the same questions as me when they were just starting out! So they can save themselves a ton of time and keep their fish happy and healthy!