Aquarium fish swim in circles when they suffer from whirling and bladder disorders, especially in an ammonia-poisoned tank. Other common reasons include overfeeding, oxygen level, water temperature, stress, and many more.
To be honest, a single solution will not work for all tank fish. Because the fish are vulnerable due to different internal and external factors. Hence, you need to know how to prevent the scenario and the treatment process that I’ve incorporated right here!
Is It Okay For Fish To Swim In Circles?
If the aquarium fish cruises in a circular motion once in a while, I assure you that there is nothing wrong. Sometimes, they like to play around in the tank, and therefore, they swim in the same direction.
Also, right before their breeding season, they show such behavior. So, do not misunderstand this indicator of fish mating as a disease.
Is Swimming In Circle A Threat To The Fish?
If your fish constantly swims in a circular motion, it is not healthy behavior at all. It reduces their lifespan as it weakens their body quicker.
Other symptoms like nibbling tank objects and reduced appetite indicate that they are swimming in a circle due to whirling disease. Also, if you see blackened tails in these fish, they might be infected by parasites. In such cases, you will need to cure them before they die.
Why Is My Fish Swimming In Circles?
Fish swimming in circles does not always indicate their playfulness. If they show the behavior constantly, then there is something wrong with the fish or the water. Based on my research, these are some of the common reasons for that:
1. Whirling Disease
In simple words, if parasites form in the water or inside the fish gill, it can cause Whirling disease. Parasites damage the neurological balance of the fish, hence, they chase other mates, swim in circles, and become aggressive.
This is common to salmonid, goldfish, and tetras species. However, if parasites get into the tank from live food, such as worms and insects, any species can suffer from this illness.
2. Swim Bladder
If you overfeed the fish constantly, they will struggle to digest the food. Gradually, their immune system will be damaged. It can lead them to swim bladder disease that affects their ability to swim.
Moreover, they will fail to swim across the water, thereby, the fish will move in circles in one area. Also, fish with affected bladders can sometimes sink in the water instead of floating.
3. Ammonia Poisoning
Ammonia is the toxic by-product of excessive fish waste and rotten food. Once this substance increases in the water, they also raise the nitrite level, which is also harmful to the fish.
Such foul water affects the gill tissue of aquatic pets. And it reduces their bladder’s functionality which aids in swimming skills. As a result, they keep swimming in the same motion!
4. Stress
Dirty water or ammonia poisoning stresses the fish, and they lose their appetite. Due to nutritional lack, they are prone to swim erratically.
Moreover, if the tank is too small and has nothing to play with, the fish stress out. And out of stress, they move around in circles.
5. Water Temperature
Fish thrive in tank water that has an ideal temperature as per their tolerance level. If the temperature goes too low or high, they can become too aggressive and prone to abnormal swimming.
As fish tanks are smaller compared to natural habitats, the water temperature easily fluctuates.
And if you place them too close to the window, the water temperature alters every now and then. When fish cannot adapt to such water, they begin swimming in a confined area!
6. Territorial Behavior
What amazes me is fish swim in this manner to set their boundary in the tank. If you have recently transferred some fish, they will express such behavior to warn other fish that it is their territory.
Such territorial behavior is safe. It is a sign that the fish are adjusting to the tank conditions.
7. Oxygen level
The oxygen level in the tank tends to go down if the water becomes too dirty. In general, the fish swims around in a particular area and gasps for oxygen.
If you do not add a filter to supply oxygen to the water, the water condition deteriorates. And without enough oxygen, they do not feel too active to swim through the tank.
8. Incorrect Diet
Live foods like worms and insects introduce parasites to the habitat. And these parasites cause swimming disorders.
Also, if you do not maintain a fixed feeding schedule, it affects the immune system of the fish. Such an incorrect diet system causes them to cruise around in circles.
9. Aggressive Mates
I’d like to remind you that not all fish get friendly with other fish tanks. If you accommodate several species of fish in the same habitat, they compete with each other.
As a result, these will chase each other in the same place, which may seem like they are swimming in circles.
10. Overfeeding
Overfeeding is one of the main factors that trigger the fish to express a fixed swimming pattern. It means that they will produce more organic waste after digesting the food.
And guess what? The waste releases a great amount of toxic ammonia into the water that makes the fish pets susceptible to disease and unusual behavior. Also, uneaten foods pollute the water, which triggers the fish to swim or float in circles.
How to Treat Fish That Swim in Circles?
Before the whirling and swim bladder disease kills your infected fish, you must be aware of treating them.
Even the diseased fish that swim in a circle can stress other healthy tank mates! So, I’d advise not delaying taking up the treatment as described below:
- With a net, catch the fish that shows symptoms of whirling or bladder disorders.
- Place the fish in a separate bowl or tank with freshwater.
- Starve the fish for 24 hours so that they digest the previously eaten food properly.
- If you have two infected fish, boil two frozen peas.
- Remove the shells of the peas and feed them to the fish.
- The peas will aid in improving their immune and digestive systems so that the fish can get rid of the bladder disorder.
- Contact an aquatic veterinarian and buy the antibiotics they recommend for your fish.
- Place the antibiotics as per the feeding instructions. Once your fish consume them, it will cure their disorders.
- Then, prepare salty water by adding one tablespoon of Epsom salt per gallon of water.
- Let the fish sit in the salty mix for 15 minutes. Meanwhile, purify their previous habitant or tank.
- Before adding the cured fish to the tank, change the water in the tank.
- Bring the water temperature to a level required for your fish.
- With an aquarium test kit, measure if the tank water nitrite and pH level are ideal for your aquatic pets. If yes, transfer the cured fish right away.
How to Prevent Fish from Swimming Erratically?
Unfortunately, there is no fixed treatment and medication for fish suffering from whirling disease that mainly causes them to swim erratically.
But from my opinion, following these prevention tips is easier than seeing your fish suffer:
- Avoid overfeeding to prevent ammonia breakdown and swim bladder.
- For cold fish water, keep the water between 18 to 23 degrees C. And for warmer fish, keep the range from 23 to 27 degrees C.
- Keep those fish together which are compatible with each other.
- Do not feed live foods as they introduce parasites.
- Frequently change the water every few weeks to maintain the oxygen level.
Conclusion
The aquarium seems beautiful if the fish moves to every corner. So, no fish owners will love to see their fish engaged in one corner.
Keep observing the oxygen level and overall water condition so that your fish cannot get affected by any disease. In addition, do not overfeed them, as it is equally liable for your fish to swim in circles. If no solution works, contact professional aquatic service.