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Swim Bladder Disorder: How to Tell If Your Floating Pet Fish Is Dead

I'm interested in pet fish, and I enjoy offering advice to aspiring fish owners.

Overfeeding can lead to swim bladder disorder in goldfish.

Overfeeding can lead to swim bladder disorder in goldfish.

Is Your Fish Lying on Its Side but Not Dead?

Have you ever found your pet goldfish floating listlessly at the top of the tank on its side? Most people who make this discovery assume that little goldie has passed on to the other side and immediately scoop them from the tank and toss them in the toilet for a traditional goldfish funeral.

Unfortunately, in many cases, the fish isn't actually dead, but rather suffering from a problem with their swim bladder due to overfeeding.

There are plenty of warnings about overfeeding fish, but many people are unaware of just how easy it is to overfeed. The danger of overfeeding is that it can lead to constipation, which can, in turn, lead to problems with the fish's swim bladder.

The swim bladder is an organ that is flexible and filled with gas. Fish use this organ to maintain their buoyancy in the water. The gas expands at lighter pressures, helping the fish to rise, and is compressed when the fish dives, which helps it descend into deeper waters.

Signs of Swim Bladder Disorder or Disease

Problems with the swim bladder can lead to the fish:

  • float on the surface,
  • sit at the bottom of the tank,
  • or even stand on its head at the bottom of the tank.

How to Resolve Swim Bladder

If you find your fish floating on its side, not feeding it for three or four days can often solve the problem as the fish's body recovers from the gorging and rights itself again.

Feeding crushed green peas can help alleviate constipation, which in turn will help the fish's swimbladder to work effectively once more. However, this should not be part of a long-term diet.

How Do I Prevent This Disorder?

There are a few things you can do to reduce the risk of your goldfish getting swim bladder disorder.

1. Test Your Water

The most important thing you can do to prevent these problems is to regularly test your water and ensure good water quality.

2. Offer a Fresh Diet

Feeding a fresh diet as opposed to fish flakes or pellets might be beneficial. Bloodworms, brine shrimp, and even small amounts of vegetables can help your fish be more healthy.

The problem may have been caused by the fish swallowing air, so pre-soak the fish food in the future to avoid this problem.

3. Change the Tank Water Frequently

You should also change your water frequently (the 50% per week rule holds here), and ensure that you do not stir around in the gravel when you change the water. Doing so can unleash nasties into the water that otherwise would stay trapped in the gravel.

4. Don't Use Tap Water

Never use water straight out of the tap. Instead, use a water conditioner and test the water for the correct pH before adding it to your fish tank.

Do Your Research

This article was meant to just cover the basics of swim bladder disorder in order to bring awareness to goldfish owners. If you suspect this might be going on with your fish, I encourage you to do more research on how you can resolve and/or prevent this issue. The resources below are a good place to begin.

Further Reading

This article is accurate and true to the best of the author’s knowledge. It is not meant to substitute for diagnosis, prognosis, treatment, prescription, or formal and individualized advice from a veterinary medical professional. Animals exhibiting signs and symptoms of distress should be seen by a veterinarian immediately.


AaLa on July 03, 2020:

Thank you that was very infromative

Carla on May 17, 2020:

My guppies gorged themselves on fry after a large female gave birth and now ive noticed two that cant swim down from the top of the tank! What do i do???

Liam Swift on May 13, 2020:

I have checked all of my water and everything is clear, however 3 of my fish have already died and one is lying lifeless. I don't think it was all because of a bladder problem and I don't know what to do

Bryson Gooden on February 28, 2020:

I have 3 guppys and i think i flushed one of my fish that was still alive..... i woke up and he was inside the filter intake but didnt look hurt and i think he got hurt then got sucked in and i put him back and he just floated there on his side so he might have still been alive

Alex riachi on June 30, 2019:

I think my fish was not dead but I buried him before knowing this

Meena on June 08, 2019:

My fish was fine yesterday, eating and swimming around. (He looked a little tired last night but I don’t know) but I woke up this morning and now he is on his side on the bottom of the tank, I have many other fishes however he is the only affected.

Anissa on May 20, 2019:

My fish is lying on the bottom of the pot but is not breathing

I think I overfed him.

What should I do?

Riya on May 16, 2019:

My fish bowl brome down . so i put my fish in a big tub but its not transparent is it okay to put them tgere i will be getting an aquarium soon

Anna Shannon on April 11, 2019:

Thank you so much for this. i have got some baby fish in my pond and was so upset to see they were lying on their side. I want to do my best for them.

Bella on March 10, 2019:

My fish was fine yesterday, eating and swimming around. (He looked a little tired last night but I don’t know) but I woke up this morning and now he is on his side on the bottom of the tank, he is an only fish. Also, this morning I came into my room and my cat was on the desk so maybe she scared him.

I don’t think he is breathing but I can’t be sure. If he is stressed I’m afraid that if I try to wake him up or move him it will cause him to become even more stressed and die ( if he hasn’t already). I need help.

paige on February 25, 2019:

my fish is floating at the surface of my tank breathing and moving her find trying to swim. I think I may have over fed her. she has a bump on her side. what do I do

Ella on February 19, 2019:

My fish might live another day!

Paytc on May 05, 2018:

My goldfish is going upside down, laying on the rocks for 2 days and she is not dead yet because she is still swimming a little bit but he is going to the top and bottom of the tank// switching about every 3 minutes, and laying there. Is there anything I can do? At all? Do you happen to have any idea what the problem may be?

Dat goldfish lover on December 07, 2017:

Thank you! You might of just saved my goldfishes life!

Susan on October 26, 2017:

Our little gold fish from the school carnival is now five years old and seven inches long. How much should I feed him a day?

Jola on June 20, 2017:

My little brothers angel fish is floating on its side at they top of the tank but still swimming and trying (but most times failing) to eat

This has been for approx.4 days now

On the second day it was back to normal but by the next day it was it was afloat again pls help

My little brother is very very sad

Kelsey ---- on December 23, 2016:

Hm... My poor Undyne is still having a problem. Is there anything else I can try?

superfreak on July 26, 2011:


Hope Alexander (author) on January 31, 2008:

Yes, pet stores and private people selling fish should really supply this basic informtion, and it is incredibly basic.

Rebecca Mikulin from Sheridan, Wyoming on January 31, 2008:

Great "basics" article! It's sad how many goldfish are inadvertently abused due to misunderstandings about their space requirements, feeding, and common ailments. I also feed mine spirulina flakes regularly to help prevent SBD, not as easy to obtain as the peas but if you run into a fish that won't eat something so different than what the pet store gave it it's worth a try :D

Hope Alexander (author) on January 30, 2008:

As a child I didn't know either, which seems very silly, as this is a very common affliction amongst goldfish and other commonly kept pet fish. It seems very remiss of pet shops to sell fish without this sort of vital information. There are probably thousands, if not millions of fish killed every year needlessly because the owners had never heard of this problem.

Stephanie Marshall from Bend, Oregon on January 30, 2008:

Ah ha..... I see now. Thanks. I never knew.

Just Toyia from Tennessee on January 30, 2008:

I had a fish with this problem and nothing helped her except temporarily, but she lived for 2 years -I wrote about it here a few weeks ago-

Raven King from Cabin Fever on January 30, 2008:

Oh, that's why I never had much luck them. Thanks. :)