Betta Fin Rot vs Fin Loss – Care and Treatment

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Betta Fin Rot vs Fin Loss, which one is plaguing your Betta? 

Fin rot is one of the most common bacterial infections in fish tanks.

It usually occurs alongside other diseases and is easily prevented with the proper care.

Fin loss is physical damage or trauma to your Betta’s fins.

Fin Rot Symptoms

One of the things that you will notice with this aquarium disease is the ragged fins on your Betta.

As time goes by, they get progressively shorter & some whiteness on the edges starts to appear.

Cotton Wool is often a secondary illness that can arise in Betta.

It manifests itself as fuzz on the fins.

Unless you intervene, the base of the fins will get red & inflamed with bloody patches appearing.

Fin Rot Causes

A weak immune system, dirty water, or overcrowded tanks can result in your Betta getting fin rot.

Prevent this from happening by cleaning the tank regularly, ensuring that the tank does not have excess leftover food and that it is large enough for all your fish.

Food particles and waste will degrade and contaminate the water if the water is not changed regularly.

Even regular water changes may not be enough to keep the disease at bay if there are too many fish or too much food in the aquarium. 

The stress that the Betta experiences as a result of this reduces his immunity, leaving him more vulnerable to bacteria present in the water.

Green betta fish with tattered fins

Fin Rot Treatment

Inspect The Tank

It’s always important to investigate when one of your fish becomes ill and figure out why.

Fin rot can recur if the underlying cause is not addressed.

Firstly, use an aquarium water test kit to check the water’s parameters.

Make sure that Ammonia and Nitrite are sitting at zero.

Check that the temperature of the water is not too low or too high.

Any one of these scenarios can cause your Betta to be stressed thereby causing disease to break out.

Observe to see if your fish are being stressed by anything in the aquarium, such as overly strong filtration or sharp-edged decor.

Correct The Situation

Once you figure out what caused your aquarium fish to get Fin Rot, fix the problem right away so they can start recovering.

Do A Water Change

Be sure to first do a 25% water change in the aquarium and remove as much fish waste as possible by vacuuming the gravel before moving on to the next step of adding medication.

Once you add medication to the tank then you will not be able to do any water changes.

Add Medication

Fin rot can be treated with a broad-spectrum antibiotic like erythromycin, which is available over the counter and in many fish stores.

You can also treat the affected fish tank with API Stress Coat or Melafix.

Methylene blue is an acceptable antifungal treatment if your fish also has a secondary fungal infection.

Follow the instructions for each medication carefully.

Aquarium salt may also work. Just be aware that it will take longer to get rid of the infection with this treatment.

If you are using active carbon in your filter then this will need to be removed before adding any medication to the tank.

Make Your Fish Comfortable

If you want your fish to recuperate quickly, keep their habitat clean and comfortable.

A sponge filter or air stone can help with medication side effects by keeping the water well-oxygenated.

How to Tell Whether the Fin Rot Has Healed?

Even though it may take a few days for the medication to work, there are several telltale indicators of improvement:

  • The rot in the fins hasn’t spread any further.
  • There haven’t been any new symptoms appearing.
  • The hunger and energy of your fish have returned.
  • The regrowth of the fins has started (and maybe a different color than before)

One of the best ways to protect against this is by keeping your fish tank clean and healthy.

The water in your aquarium should be kept clean at all times to prevent the growth of bacteria that can lead to infection.

You can also help by not keeping too many fish in one aquarium, not overfeeding them, and using living plants to help absorb some of the waste from your fish.

Blue betta fish hovering above the gravel in a fish tank

Preventing Fin Rot

Keeping your water clean and your aquarium in good condition is the most effective strategy to prevent fin rot and other fish diseases.

Change the water on a regular basis.

Maintaining a clean tank and doing regular water testing can assist you in identifying any issues with water quality before bacteria accumulate and cause fin rot to develop.

It is also important to test the pH & temperature of your water regularly to avoid problems with Fin Rot.

All fish, particularly Bettas, are more prone to this problem when the temperature of their water is either too low or too high.

Try not to overcrowd your tank because waste can accumulate quickly and fish may nip at one another if there is not enough space for everybody.

Despite the fact that fish are quiet and serene to observe, not all species of fish get along well.

Always check your fish’s compatibility with each other before introducing new tank mates to avoid any fin nipping or fights between your fish buddies.

When feeding your fish, use tiny amounts of fresh, high-quality food to ensure that they get enough to eat.

In general, your fish should swallow the food that you offer them within a few minutes of being fed.

Any food that they do not consume completely can contribute to the growth of germs and waste in your tank, which can lead to fin rot.

Feeding time is also an excellent opportunity to pay close attention to your Betta’s behavior.

Keep a close eye out for any changes in their fins, tails, physiques, appetite, or behavior on a daily basis.

Is it Fin Rot or Fin Loss?

Many people mistakenly believe that fin rot and fin loss are the same thing, yet the two disorders are very distinct.

After all, we’ve shown that fin rot is an easily treated bacterial infection that is frequently caused by poor water conditions, which can leave your Betta vulnerable to fin rot.

A sign of fin rot is if your Betta’s fins start to darken or bleed, or if any tissue starts to peel off.

Because of this loss of fin tissue, Betta owners may mistakenly believe that their fish has fin rot when they actually have fin loss.

So, how will you be able to tell if it is Fin Rot or Fin Loss?

Fin Loss

The good news is that fin loss is not a medical condition.

Physical damage has been caused by something in the tank, and fortunately, fixing it is rather simple and straightforward.

Split or torn fins, as well as small, pin-sized holes in the fins, are all signs of fin loss.

Because bettas’ fins are so sensitive, it is common for them to lose their fins due to something in their tank, such as:

  • Decorations in your tank
  • Plants made of plastic (Use silk plants instead)
  • Fish that tend to nip
  • The intake of your filter is too strong

Aquarium Decorations

Bettas’ long, flowing fins can get caught on objects in the aquarium, such as driftwood or bogwood.

Sharp rocks and plastic decorations or plants may also cause damage to their delicate fins.

A simple test can determine the cause of fin loss to your Betta.

Take a normal pair of women’s nylon pantyhose and run it over all the decorations in your tank.

If the pantyhose gets snagged then that item can cause fin loss and damage and you need to remove it from the tank.

Some decorations can be filed down so that they are smooth so you can give this a try instead of tossing it.

Plastic plants should be avoided and never put in the same tank as your Betta. In most cases, these are the culprit even if they feel soft.

Rather use live plants which will help with water quality or artificial silk plants will also do.

Make sure there are no sharp rocks either.

A blue betta fish swimming past a decoration in a fish tank

Fish That Nip

You might think that Bettas are aggressive and therefore should be able to fend off fish that will try and nip them but this is not the case.

They are actually quite vulnerable because of their flowing fins that can attract unwanted nipping.

Avoid adding tank mates like Tiger Barbs or larger fish that could view your Betta as a snack.

If you notice any fish nipping at your Betta then it would be best to either remove the offending fish or move your Betta to another tank.

The Filter Intake

If the filter intake has a strong suction then your Betta’s fins may be pulled or snagged, or they may become caught in the intake tube or be sucked in.

If this is the case then check to see if you have the right filter or reduce the filter’s flow rate.

Fin Loss Treatment

To resolve the problem, it must first be identified as fin loss rather than fin rot.

 The fin loss should stop and begin to mend itself once you’ve dealt with the sources of the problem, whether they’re plastic plants, bogwood, or fish that bully each other.

It’s common for Betta fin tissue to repair quickly, but be on the lookout for fresh tears, splits, or holes developing in your Betta’s fins, which could indicate that you missed something.

It’s also a good idea to keep an eye on the fin damage to make certain that no infections develop and complicate treatment.


Fin rot and fin loss are both common problems with Betta fish, but once you know what to look for, you will know how to correctly – and quickly – treat each issue.

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Irma Bense is the founder of She has over 42 years of experience in keeping fish.She has kept both freshwater and saltwater fish through the years.She has extensive knowledge in breeding numerous species of fish from Show Guppies, Cory Catfish, German Blue Rams to Apistogrammas.You can learn more about Irma on the 'About' page.

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