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10 Common Rasbora Diseases and Problems

10 Common Rasbora Diseases and Problems

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

Rasboras are good fish that are easy to take care of even for beginners. Usually, you’re not going to encounter many problems when keeping these fish in your home aquarium.

However, things can go wrong and the fish might get sick. Sometimes fish will get sick if they’ve become stressed for one reason or another.

There are certain types of diseases and problems that are common for rasboras. Read on to learn about these common issues so you can know what to expect.

Catching diseases fast will allow you to take action and protect the fish. You can also work to prevent these things from happening by doing your best to focus on tank maintenance.

1 – Furunculosis

Furunculosis is a chronic condition and it’s also dangerously contagious. It’s caused by the presence of gram-negative bacteria.

When fish get this disease they will get lesions on their bodies that are reminiscent of boils. A rasbora might experience darkening skin, rapid breathing, lethargy, and a loss of appetite.

It can be treated using antibiotics, but you need to catch it fast. Do your best to keep recovering fish from getting stressed so they can survive and get back to normal.

2 – Mouth Fungus

Mouth fungus is a bacterial infection that sometimes impacts rasboras. Usually, it’s only a problem in fish tanks with poor water quality.

You might notice cotton-like white patches near the mouth of the infected fish. When fish are infected they will produce stringy feces as well.

Treating the fish involves simply getting the water quality under control. Ensure that the water has the right pH balance and that there are no issues with elevated ammonia, nitrate, and nitrite levels.

3 – Pop Eye Disease

Pop eye disease can be caused by quite a few things. It can be caused by an infection in the eye, but it can also occur after a fish has been injured near its eye.

When a fish has pop eye disease its eye will bulge from the socket. A fish can go blind or even lose an eye if it doesn’t receive treatment.

To treat the fish, focus on keeping the water quality high. The fish might need antibiotics if it has an infection.

4 – Dropsy

Dropsy is a condition that sometimes impacts tropical fish such as rasboras. This involves swelling in the abdominal region and it causes fish to not be able to swim properly as well.

Usually, this issue is caused by poor nutrition or elevated ammonia and nitrite levels in the aquarium. You should try to fix things in the tank right away and start treating the fish by adding aquarium salt to the tank.

Fish can get better over time, but you need to do more regular water changes. Focus on tank maintenance and dropsy won’t likely ever become a problem.

5 – Columnaris

Columnaris is a contagious disease that rasboras often have to deal with. This is a condition that causes flat white patches to form on the body of the fish.

Often, this disease is mistakenly identified as a different fungal infection. Fish that have columnaris show signs of lethargy and they don’t eat as much as usual.

Columnaris is caused by poor nutrition, overcrowding in the tank, and generally poor water quality. To treat columnaris, fish will need to be given antibiotics.

6 – Fin Rot and Tail Rot

Fin rot and tail rot are both bacterial diseases. This is a type of infection that will cause either the tail or fin to rot away.

Typically, this disease is caused by extremely poor water quality. Dirty water makes it so bacteria can thrive in the tank.

Stressed fish are more likely to deal with these issues. It can be treated with antibiotics, but you need to address the issues in the tank to take care of what caused the fish to get sick.

7 – Hole in the Head Disease

Hole in the head disease is caused by parasites and it creates holes on the head as well as other parts of the body. This is a disease that can easily kill your rasboras.

The holes will keep getting larger unless you treat the fish. Treating this condition involves giving the fish medicated fish food, closely monitoring water quality, and doing your best to provide the fish with an ideal environment.

Poor water quality and overcrowding seem to make it more likely that fish will deal with the parasites that cause hole in the head disease. It’s better to prevent this disease since it’s not always possible to save the fish even when you take action fast.

8 – Anchor Worms

Anchor worms are another type of parasite that attach themselves to your fish. These worms will dig their way into the body of the fish.

You can see the worms sticking out of the fish just a bit if you examine them. Often, the area where the worm is present will have a red appearance.

Fish with anchor worms will feel lethargic and they might have a hard time breathing. This condition should be treated with potassium permanganate as well as physically removing the worms with tweezers.

9 – Ich

Ich is also commonly referred to as white spot disease. This is a very contagious condition that is caused by parasites.

When fish contract ich they will have white spots appear all over their bodies. They might have trouble breathing, they’ll appear to be very uncomfortable, and they’ll try to rub against objects in the tank.

This condition must be treated using anti-parasitic medications. It’s common for people to use aquarium salt to add in the treatment and raising the temperature of the water can help to get rid of parasites, too.

10 – Velvet Disease

Velvet is yet another parasitic disease that you need to know about. A parasite called Oodinium causes this condition and the skin might peel off of your fish if it isn’t treated fast.

Fish with velvet will deal with clamped fins, weight loss, lethargy, and yellow or brown film that covers the body. It can be very problematic, but this is a treatable disease.

Increase the water temperature and add aquarium salt to the tank. Copper sulfate can be used to medicate the water and get the fish back to being healthy.

Why Is My Rasbora Losing Color?

Normally rasboras will lose color when they’re experiencing stress. It’s likely that something in your tank is causing your fish to feel off.

You might need to monitor the water parameters closely. If there are issues with the water temperature, pH balance, or other things, you should address them fast.

Overcrowding in the tank can also cause fish to become stressed. Do you have enough room for all of the fish in the tank?

Not cleaning the fish tank enough is stressful for the fish as well. Poor water quality can easily make your fish sick.

Why Is My Rasbora Jumping?

Rasboras are known to jump out of aquariums if they feel stressed. So your fish might be jumping because they’re stressed.

You should keep a lid on the fish tank just to be safe. This keeps the fish from being able to jump out of the tank.

Solve any things in the tank that are causing the fish stress. For instance, they might be getting bullied by their tank mates.

Why Are My Rasboras Fighting?

It’s not common for rasboras to fight each other. They’re peaceful fish that don’t have a reputation for being aggressive.

However, fish will start to act strangely when they’re stressed. Stress might cause the fish to fight each other or become territorial.

Sometimes rasboras might go through situations like this when they’re put in a crowded fish tank. These are schooling fish, but they still need enough room to thrive.

Why Do My Rasboras Keep Dying?

If your rasboras keep dying, it’s likely that you’re not doing regular tank maintenance. Rasboras are hardy fish and they’re considered to be easy for beginners to care for.

That might be disheartening to hear, but people normally don’t have a tough time keeping these fish healthy. If yours keep dying, you might be keeping them in an improper environment.

Make sure that the rasboras are being kept in the right water conditions. The temperature and the pH balance need to be in the right range for the fish to thrive.

Test the water every few weeks to see if it’s in the right range. Feed the fish well and make sure that you put them in a fish tank that’s large enough for them.

Remember that rasboras are meant to be kept in small schools, too. Most people buy at least six or seven of them for one tank.

Why Is My Rasbora Swimming Upside Down?

If you see one of your rasboras swimming upside down, it is surely experience a swim bladder problem. The swim bladder is an organ that controls buoyancy.

Sometimes fish will eat too much at once and become constipated. They’ll have their bellies swell and then that will press against the swim bladder.

A swim bladder is a gas-filled sac that inflates and deflates as necessary. If the belly is pressing against the swim bladder, it cannot function properly.

Be sure to avoid overfeeding your fish. Feed rasboras twice per day and give them only as much as they can eat in two or three minutes.