Betta Fish Fin Rot—Will The Fins Grow Back After Treatment

Betta Fish Fin Rot—Will The Fins Grow Back After Treatment

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One day you may notice a chunk missing from your betta fish fins. Which usually happens too quickly you’d easily assume it’s a nipping. However, this could actually be fish rot, a common but preventable aquarium fish disease.

That said, in this article, Ill answer common questions almost every betta fish owner ask regarding the mysterious fin loss.

Please note I’m not a veterinarian, and I’m just passing on my experience and things I’ve learned over time mostly from the internet and while keeping fish.

What is ‘Betta’ Fin Rot?

The reason I’ve got quotes on the word betta in the heading above is that fin-rot is not reserved to betta fish. It is a disease that can affect a variety of aquarium fish, including goldfish.

It’s, however, more conspicuous in fish with flowy fins and tails like bettas.

Fin rot is a bacterial infection that occurs together with other diseases in most aquariums, it’s often caused by hosting fish in a dirty tank that is poorly kept or exposure to fish with other infectious ailments.

A thing to note is, the infection is not always bacterial, at times it could be a fungal infection. Plus it’s also called fin melt or tail rot.

Fin rot manifest in the form of torn and ragged fins which may fade with time and eventually fall off.

When left to prolong, it will gradually take a toll on your betta making it lethargic and discolored and may cause permanent damage to the fish’s fins.

That said, the pathogens that cause fish rot though regularly in your aquarium, won’t always infect your fish. If the betta is healthy, its immune system will overcome the pathogens.

So, it’s imperative to not only stay ahead of fin rot, but any disease doing rounds in your tank.

By and large, don’t panic if your betta is infected, fish rot is common but rarely is it fatal. The infectious bacteria in your water will only be dire if your betta has a weak system. Which is an issue easily solvable by taking better care of the fish.

How Do You Tell Whether Your Betta Fish Has Fin Rot?

Fin rot usually gets more prominent on the tail fin than on the dorsal and pectoral fins. It’ll mostly show up on the tips first in rugged patches due to a breakdown of the fins’ protective layer.

As the disease progress, it will continue to spread across the fin and eventually get to other fins that were previously not affected. The flips will then become shorter as dead flesh peel off the affected parts.

Sometimes, holes will appear on the infected area which is mostly a fungal infection occurring together with fin rot.

As the infection advances, you could notice discoloration on your betta, particularly intense on the most affected parts. The fin will also have uneven white lining and white dots or red streaks from inflammation and bleeding.

In very severe cases, your betta fish might get ulcers on the fins maybe even the body. And eventually, the flips will gradually fall off in chunks.

Sadly, a major hurdle is detecting fin rot in the early stages of the infection because the signs start very subtly. Most betta owners will only detect the disease when it’s quite advanced, and some when the fins start to fall off.

Consequently, fin rot that goes undetected at times kill the diseased betta or infect other fish in the tank.

What Cause Betta Fin Rot?

Betta fin or any fin rot, in general, is caused by different types of gram-negative bacteria, including Aeromonas, Pseudomonas Flourescens and Vibrio.

These bacteria eat away the membrane on the betta’s fins leaving them with the rugged and frayed look. The damaged tissues are also left vulnerable to fungal infections which usually manifest as a secondary infection to fin rot.

By and large, the bacteria will thrive in poorly maintained unhygienic tanks.

In fact, with poor water quality, the bacteria will not only overgrow and spread the infection but also increase the chances of other diseases showing up.

Other common catalysts include overfeeding your betta fish which contribute to poor water quality and overcrowding hence too much waste.

In other cases, the low water temperature may be the cause of the infection.

Lastly, though fin nippings arent synonymous with fish rot, injury on nipped fins could accelerate an infection from the fin’s apparent weakness.

Betta Fin Loss— Fin Rot vs Fin Nipping

Nippings by other fish on your betta is different from fin rot, you will mostly see the fins disappear without a clear edge and sometimes see bite marks on the fish body.

Plus the victim fish will usually hide from the perpetrator.

Also, if your aquarium water quality is perfect, any missing fins on your betta will most likely be nippings and not fin rot.

Another thing to consider, is that yours is a betta fish, therefore, it’s most likely the nippers and not the victims. Unless you’ve committed the classic rookie mistake and put your betta together with other nippers like Gouramis (dwarf gourami, pearl gourami”)dwarf gourami), and barbs.

To be sure in toto, look for white linings on the affected fins or spots and reddish lesions. If any of these signs can be identified, you are most likely looking at fish rot.

But if all you see are general bite marks, then that’s just a fin nipping situation going down.

In which case, you should consider separating the fish because most territorial fish will continually get aggressive until the threat is moved.

Can Fin Rot Kill Your Betta—Does it Hurt The Fish?

As I mentioned before, betta fin rot is one of the most common diseases in aquarium fish, hence there are ways to treat the infection. Meaning the disease doesn’t have to be life-threatening.

That said, I’d assume the rotting fins and ulcers on the fish body in severe cases definitely do hurt your fish. Your betta may even start rubbing against the tank walls or on decorations to try and relieve the discomfort. Which, unfortunately, only make the disease worse and further damage its fins.

Still, in severe cases, fin rot left untreated will reach the fish body and leave your fish unable to swim or dead in the worst case scenario.

Plus, the rot is a precursor to other infections, though not fatal on its own, the reduced fish immunity will leave you betta vulnerable. Should the accompanying ailment be potent enough, it will very likely to put your betta down.

How to Treat Betta Fin Rot

To properly deal with betta fin rot, we first need to remove the cause of the infection from the aquarium.

Not to say you have to clean your aquarium like crazy pants, but you need to maintain a reasonably healthy environment.

Cleaning Up

You should aim to improve the overall quality of the water in your betta tank to help cycle out the disease-causing bacteria.

While cleaning your tank, take the betta out and place it in a separate tank with clean uncontaminated water.

Assuming you use a net to move your fish, there is a need to use a different net to move the infected fish and another for any healthy fish. Plus don’t place the infected fish in the new tank with the others.

Better still, set up a different tank to act as a quarantine, this will help you treat your betta without running the risk of infecting the rest. Besides, if any other fish gets infected later, you will always have that extra tank at your disposal.

After draining your original tank, you’ll want to clean it with hot water. And also clean all the accessories as well, including vacuuming the substrate.

However, while cleaning, avoid using soap or detergents in the fish tank because soap residue could be fatal to your fish.

Make sure you change 100 percent of the water in the tank. In fact, once you clean the aquariums and all accessories, let them dry out completely before replacing them.

One last thing you want to check is your new water conditioner. Ensure the temperature and the pH is appropriate for freshwater fish, just to be sure it’s not part of your problem.

Also, make sure your aquarium filters are working properly and clean them where necessary.


Once you’ve cleaned your tank or placed your betta in a quarantine space but the fish rot persists, then its time to consider medication.

Use aquarium antibiotics made to treat a gram-negative bacterial infection, the medication should also kill fungal infections too.

You can buy them over the counter at your local pet store or online. While on Amazon, you’ll even get veterinarian treatment guides.

A popular type of this medication is Tetracycline.

Once the bacteria have died down, Bettafix will help heal bloody fin tips and regenerate new tissue. Bettafix on its own, however, is too mild to treat severe fish rot.

Do Betta Fins Grow Back After Fin Rot Treatment?

Yes, your betta fish fins should gradually grow back if adequately treated and the water quality improved.

When the new fin tissues begin to grow they’re often clear and very thin hence very delicate and may easily get injured again, so continue with the treatment until the fins are fairly grown.

The most important things to do during regrowth are to monitor your betta fins and to replace its water so that bad bacteria have little chance to take advantage of any open wounds.

Also, once you put your betta back in the water after cleaning the tank, continually check the water for ammonia, nitrites, and nitrates.

Plus prop up your water changing schedule.

If you didn’t have an aquarium filter installed before, consider buying one. Look for one with good biological filtration capabilities.

Lastly, bettas are rather sensitive to salt, so it’s actually better to skip that unless the infection you are treating specifically calls for a salt bath.

However, there are instances when some aquarist treats fish rot with tea tree oil and salt, but this is not reliable as a cure, only as a preventative measure.

Have fun with your healthy betta

Eddie Waithaka

Resident Content Creator and Marketer at AquariaWise who talks about aquariums and fish and aquascapes a lot.

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