Cory catfish are bottom dwellers and spend most of their time scavenging the bottom in search of food. Cory catfish swimming at the top of the tank will worry us as it is not their normal behavior. So, Why are my cory catfish swimming at the top? Let us find out.
Oxygen deficiency is the reason behind your cory catfish swimming at the top of the tank. Other causes include poor water conditions, swim bladder disorder, overfeeding, and an ammonia spike. Ensure good water conditions and add an air pump to your cory catfish tank to prevent such issues.
This article will discuss why cory catfish swim at the top of the tank and how we can prevent such issues. So, let us get into it.
Contents
My cory catfish are swimming at the top of the tank.
Cory catfish will often come to the tank’s surface to gulp air with the mouth.
It is normal behavior, and nothing is there to worry about.
However, if your cory catfish is showing such behavior more often, it is a matter of concern.
Lack of oxygen is the reason behind your cory catfish swimming at the top of the tank.
There can be other various reasons like poor water conditions, ammonia spike, swim bladder disorder, and high-level stress.
A tank will lack oxygen if it is overcrowded, has bad water quality, and lacks aeration on the water’s surface.
Is It normal for my cory catfish to swim at the top of the tank?
Cory catfish swimming at the top of the tank is normal when:
- They are coming up to eat the food.
- They are sometimes coming up for gulping air with their mouths.
Cory catfish are bottom dwellers and spend most of their time scavenging at the bottom of the tank in search of food.
However, cory catfish can also come to the water’s surface if they see an opportunity to eat.
It is normal when they sometimes come to the top of the tank to gulp air with their mouths.
But, it is a matter of concern if they are constantly coming to the top of the tank.
The deficiency of oxygen is the reason behind your cory catfish staying at the top of the tank most of the time.
Poor water conditions result in a lack of oxygen in the tank.
Other reasons behind your cory catfish swimming at the top of the tank can be swim bladder disorder, overfeeding, and ammonia spike.
We will discuss many other reasons that result in a lack of oxygen in the tank in the further article.Â
What are the reasons behind cory catfish swimming at the top?
These all can be the reasons behind your cory catfish swimming at the top of the tank:
- There is a lack of oxygen in your cory catfish tank.
- You cory catfish is suffering from swim bladder disorder.
- There has been an ammonia spike in your cory catfish tank.
- You have overfed your cory catfish.
- Your cory catfish is under a high level of stress.
Deficiency of oxygen
Lack of oxygen is the common reason your cory catfish swim at the top of the tank.
Usually, cory catfish come to the water’s surface to gulp air with their mouth.
Cory catfish are intestinal breathers and will show such gulping behavior.
In their natural habitat, cory catfish used to come to the surface to gulp the air with their mouth when there is intense heat and the oxygen level is deficient.
If your cory catfish is showing such behavior more often, there is a lack of oxygen in the tank.
The following reasons can lead to a lack of oxygen in your cory catfish tank:
- Lack of aeration in the water.
- Overcrowded tank
- Poor water conditions
The tank’s surface holds the most oxygen in the aquarium, and your cory catfish will prefer swimming at the top of the tank when there is a lack of oxygen.
A lack of oxygen can also result in an ammonia spike.
You must know that the beneficial bacteria present in our aquarium require oxygen to break down harmful toxins like ammonia and nitrite.
When there is a lack of oxygen in the water, beneficial bacteria will not be able to break down harmful toxins, resulting in an ammonia spike.
Also read: Do Cory Catfish Need Oxygen?
Swim bladder disorder
Swim bladder disorder can also be the reason behind your cory catfish swimming at the top of the tank.
The swim bladder helps the fishes to maintain their buoyancy.
Cory catfish suffering from swim bladder disorder will not be able to maintain its buoyancy and will either sink to the bottom of the tank or will float at the surface.
All these are the symptoms of swim bladder disorder:
- Sinking to the bottom of the tank.
- Floating at the top of the tank.
- Bent spine
- Swollen belly
- Swimming up and down erratically
- Losing its appetite
Overfeeding, gulping air, infections, and blowing on hard objects are the common causes of a swim bladder disorder.
It is also possible that your cory catfish have a swim bladder disorder because of genetics. The symptoms can be seen in the early stages of such cases.
Follow these steps to treat your cory catfish from swim bladder disorder:
- Let your cory catfish have a fast for two to three days if an enlarged abdomen or intestine is the reason behind swim bladder disorder.
- Maintain the water temperature between 78-80 °F.
- After two to three days, feed boiled peas to your cory catfish, as peas are rich in fiber and will help cure constipation.
- If infections or parasites are the reason behind swim bladder disorder, then antibiotics are needed, and consider consulting your veterinarian.
Also read: Why Is My Cory Catfish Floating?
An ammonia spike
An ammonia spike can also be the reason behind your cory catfish swimming at the top of the tank.
Usually, ammonia spikes in a new tank, but it can also occur when water conditions are poor in a well-established tank.
These all can result in an ammonia spike in a tank:
- Overcrowded tank
- Poor water quality
- Leftovers of fish
- Lack of oxygen
- Poor filtration system
An ammonia spike will result in ammonia burns, affecting your cory catfish gills and body.
Cory catfish with affected gills will spend most of their time swimming at the top of the tank, gasping for air.
Also read: Why Is My Cory Catfish Not Moving?
Overfeeding
Overfeeding can also be the reason behind your cory catfish swimming at the top of the tank.
Overfeeding will make your cory catfish constipated, resulting in an enlarged abdomen.
Your cory catfish will find it harder to swim with an enlarged abdomen and remain at the tank’s bottom or float at the top.
An enlarged abdomen can also result in swim bladder disorder.
Feeding dry food that expands when it gets wet inside your cory catfish’s body is the common reason behind an enlarged abdomen.
High-level of stress
Stress can also be the reason behind your cory catfish swimming at the top of the tank.
Cory catfish are peaceful fish and do great with other peaceful fish in a community tank.
When you add aggressive fish in their tank, the aggressive fish will constantly chase your cory catfish and try to hunt them down.
Cory catfish, constantly chased by the aggressive fish, will come under stress and can even try to jump out of the tank to save themselves from the aggressive fish.
They will remain at the top of the tank or spend most of the time hiding at the bottom.
Other reasons behind stress can be:
- Overcrowded tank
- Illness
- Injury
- Unstable water temperature
- Poor water conditions
How to prevent such problems?
Ensure these things to prevent such problems:
- Provide your cory catfish with good water conditions.
- Ensure adequate and stable water parameters
- Add an air pump to your cory catfish tank.
- Avoid overcrowding your cory catfish tank.
- Avoid overfeeding your cory catfish.
- Provide your cory catfish with a stress-free environment.
Good water conditions
Poor water conditions are the primary reason behind the lack of oxygen in the water.
A tank with a lack of oxygen will result in your cory catfish swimming at the top of the tank most of the time, gasping for air.
Perform a weekly water change of at least 35% to keep the water clean.
Consider adding a good filtration system with biofilter media to protect your cory catfish tank from harmful toxins like ammonia and nitrite.
Also, heading the filter pipe from where the fresh water is coming into the tank upside will help in aeration the water’s surface.
| Particulars | Cory Catfish Requirement |
|---|---|
| Water Quality | Clean water condition |
| Water Hardness | 5 and 19 dGH |
| Ammonia | 0ppm |
| Nitrite | 0ppm |
| Nitrate | Below 20ppm |
Keep a regular check on ammonia levels and ensure to keep the ammonia and nitrite at 0ppm, whereas nitrate is below 20ppm.
We suggest using the API ammonia test kit to check ammonia levels as it shows accurate results.
You can purchase it from Amazon API TEST KIT.
Also, make sure to dechlorinate the water before adding it to your cory catfish tank when performing a water change.
We suggest using the API water conditioner to treat the water as it eliminates chlorine, ammonia, nitrite, and heavy metals from the water.
You can buy this product on amazon: API TAP WATER CONDITIONER.
Ensure adequate and stable water parameters
Ensuring adequate and stable water parameters will help you prevent such issues.
Cory catfish living in inadequate water will come under stress and become prone to various diseases and parasites.
Living in hot water temperature will slow down the digestive process, resulting in an enlarged abdomen and loss of appetite.
| Particulars | Cory Catfish Requirement |
|---|---|
| Water temperature | 72-82 °F |
| Water pH level | 7-8 |
Provide your cory catfish with a water temperature between 72-82 °F.
Ensure to maintain the water pH level is between 7 and 8.
The water dGH level should be between 5 and 19.
Consider adding a heater to your cory catfish tank to stabilize the water temperature.
Also read: Ideal Water Temperature For Cory Catfish?
Add an air pump
An air pump will help create aeration in the tank water’s surface.
Aeration on the water surface is important to increase the oxygen level in your cory catfish aquarium.
The filter will also help in creating movement on the water’s surface.
Point the outflow of the filter upside to create a movement on the water’s surface.
Avoid overcrowding
An overcrowded tank will lack oxygen, making your cory catfish suffer breathing, and they stay at the top of the tank most of the time gulping air.
An overcrowded tank will also result in an ammonia spike.
To ensure you are not overcrowding your cory catfish tank, follow the one-inch one-gallon rule.
The one-inch one-gallon rule means one inch of fish per gallon of water.
Cory catfish can be as long as 4 inches in size, which means you can keep one cory catfish per 3 gallons of water.
Also read: How Many Cory Catfish In A 10-Gallon Tank?
Avoid overfeeding
Overfeeding can make your cory catfish constipated and result in an enlarged abdomen.
An enlarged abdomen will affect the swim bladder, and there will be a risk of a swim bladder disorder.
To ensure you are not overfeeding, provide them with food in a quantity that they can finish eating in 1 to 2 minutes.
If your cory catfish is taking more time to complete their food, you are overfeeding them.
Also read: How Often To Feed Cory Catfish?
Provide a stress-free environment
A stress-free environment for your cory catfish will help you prevent such issues.
Ensure these things to provide a stress-free environment to your cory catfish:
- Perform a weekly water change of 35%.
- Add a heater to keep the stable water temperature.
- Maintain the ammonia and nitrite level at 0ppm.
- Ensure to keep the water pH level between 7 and 8.
- Avoid adding aggressive fish to your cory catfish tank.
- Avoid overfeeding your cory catfish by feeding them in a quantity they can finish eating in 1 to 2 minutes.
- Add an air pump to your cory catfish tank.
- Keep cory catfish in a group of at least 5-6.
- Avoid overcrowding your cory catfish tank by following the one-inch one-gallon rule.
- Feed your cory catfish regularly, one to two times a day.
Also read: How To Tell If A Cory Catfish Is Stressed?
Conclusion:
Cory catfish are intestinal breathers and will come to the tank’s surface to gulp air with a mouth.
However, if your cory catfish is constantly swimming at the top of the tank, it is a matter of concern as the lack of oxygen is the reason.
Other reasons include swim bladder disorder, poor water conditions, inadequate water parameters, and an ammonia spike.
Add an air pump to your cory catfish tank to ensure aeration and enough oxygen for your cory catfish.
Provide good water conditions, avoid overfeeding and overcrowding, and maintain adequate water parameters to prevent such issues.
Reference: ResearchGate, NCBI, Wikipedia