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Why Is My Cory Catfish Not Eating? (7 Common Causes)

Why Is My Cory Catfish Not Eating? (7 Common Causes)

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This post is written to the author's best knowledge and is not intended to be used in place of veterinary advice. In addition, this post may contain affiliate links. As an Amazon Associate I earn from qualifying purchases.

Overall, cory catfish are great fish that will be good for beginners to care for. These fish are relatively hardy, and that makes them good choices for anyone who is just getting into aquariums as a hobby.

These fish aren’t picky eaters since they’re omnivores. You generally won’t have a hard time getting them to eat.

This is why it’s so strange when the fish don’t eat normally. If a cory catfish isn’t eating, then it could be a sign that something is amiss.

Keep reading to learn some of the reasons why cory catfish might stop eating. This will help you to figure out what might be going on in your situation.

1 – The Fish Might Just Need Time to Acclimate

Often, fish need a bit of time to get used to a new fish tank. If you recently bought the cory catfish, then they might not feel comfortable in the aquarium yet.

It has been known that cory catfish will be exceptionally shy for the first several days in a new tank. They will need time to feel things out before they will start acting normally.

Typically, the cory catfish will start to feel normal after two or three days have passed. In some situations, the fish have not become comfortable enough to start eating for around one week.

These fish can survive for a week without eating food if necessary. So don’t panic too much and hope that the fish will acclimate to their new environment soon.

It’s also important to note that taking the time to acclimate the fish properly will help them to feel more comfortable in the early days. This means floating the bag and slowly adding water from the tank into it so that they can get used to things faster.

Many people rush to put the fish into the fish tank. Not doing the floating acclimation process correctly can lead to these issues.

2 – Loneliness

Bandit Cory Catfish

In case you don’t know, cory catfish are supposed to be kept in groups. These fish are schooling fish that should be kept in groups of six or more in an aquarium.

If there are too few cory catfish in the aquarium, then they might feel uncomfortable. These fish get very lonely when kept alone, too.

In fact, it’s possible for cory catfish to die of loneliness. You must have the right number of fish in the tank so that they can do well.

The fish might not eat if you don’t have enough of them in the tank. They simply won’t ever feel comfortable in the tank, and the fish might even wind up dying because of it.

3 – Bullying Issues

Bullying issues could also be to blame for what is happening with the cory catfish. Cory cats are some of the best community tank fish you will find.

However, this doesn’t mean that they can be put in a community tank with any type of freshwater fish. Cory catfish are very peaceful, and they can get bullied by aggressive fish.

You might have put the cory cats in a fish tank with fish that are bullying them. This will make them want to hide and they might not feel comfortable enough to come out and eat when it’s time.

It’d be beneficial to double-check the compatibility of all of the fish in your aquarium. If some of the fish aren’t compatible, then you’ll need to place them in a separate tank for the safety of the other fish.

4 – Problems with the Water Quality

Issues with water quality can keep cory catfish from eating normally, too. You might be keeping the fish in dirty water that is making them feel sick.

Remember that it is imperative to monitor the water parameters when caring for fish. Perhaps you haven’t been checking the pH balance and things have gotten out of control in the tank.

Cory catfish are very susceptible to high ammonia, nitrate, and nitrite levels. Nitrite poisoning even has the potential to kill cory catfish suddenly.

Do your best to keep the water parameters in the right range for the cory cats. Remember to clean the fish tank and do regular water changes as well.

5 – Overcrowded Fish Tank

Corydoras in Community Tank

Trying to cram too many fish in a small fish tank will be detrimental. Many types of fish will become stressed and stop eating when they’re placed in an overcrowded tank.

Since the cory cats are good community tank fish, this is a common issue with beginners to the hobby. Sometimes beginners will try to put too many fish in a smaller aquarium by mistake.

Always look into how much space each fish requires. Remember that you need enough space for at least six cory catfish as well as any tank mates that you’d like to add to the community tank.

Do things the right way and only add as many fish as you will be able to comfortably fit in the tank. It’d be better to get a second tank or to procure a larger tank than it would be to overcrowd your current fish tank.

6 – The Fish Could Be Sick

Of course, sickness can make fish stop eating. Some types of diseases will cause fish to appear sluggish, and they will also lose their appetites.

You should monitor your fish so that you can take note of any symptoms. There are many types of diseases and infections that can cause cory catfish to stop eating.

Figuring out what is wrong might require you to pay close attention to the fish. You can also enlist the help of an exotic veterinarian if you want to get a fast and accurate diagnosis.

Treat the fish and try to address any issues in the tank that might have caused the fish to become sick. It should start eating again if you caught things fast enough and are able to determine the right treatment options.

7 – The Cory Catfish Simply Doesn’t Enjoy the Food

Peppered Cory Catfish Eating Algae Off of a Plant

Have you considered that the cory catfish simply might not like the food that you’re giving them? These fish aren’t picky eaters, and that means that this isn’t the most common issue to have.

Since cory cats are omnivores, they’re going to eat many types of things. They can still get bored when you try to feed them the same food all the time.

Try to mix up the food that you’re giving the fish. They will likely eat sinking nutritional pellets most of the time, but you can also give them algae wafers, veggies, freeze-dried bloodworms, and other types of food.

Simply changing up what you’re offering the fish might help. See if you can get the fish to want to eat by giving it something new that is appropriate for cory catfish.

Final Thoughts

It should be possible to get your fish to start eating normally again. You just need to determine what is wrong with the fish.

The fish might be sick or it could just be tired of the food that you’re feeding it. Observe the fish to determine what changes you need to make.

Loneliness can keep fish from eating normally in the fish tank. Cory cats might even stop eating if the conditions in the tank aren’t right.

You’ll be able to figure it out and get things back to normal so long as you put in the effort. Your cory catfish should be just fine and you’ll be able to care for them better moving forward.

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Monday 13th of November 2023

I have a 10 gallon with 3 cories. I used to have 5 of them but 2 of them died from diseases. I tried to save them- bought medications for ick (since a few have white spots) and 2 of my tetras have fin rot (also got melafix for them). I used a small dose of ick medication fizz yesterday and today they are not eating at all! Should I do a 50% water change? Though I have just cleaned their tank yesterday...

Thank you an advance!