Fin & Tail Rot

Fin and Tail Rot

Did you know that one of the most common diseases in aquarium fish is fin and tail rot? This condition can cause fins and tails to become shredded, discolored, and swollen. 

And in severe cases, the disease can even lead to death. 

Fortunately, there are several things you can do to prevent and treat fin and tail rot in your fish. 

In this article, we’ll discuss what fin and tail rot are, what causes it, and how to treat them. 

So, without further ado, let’s jump into details.


Fin rot is a common problem among tropical fish, especially those kept in freshwater aquariums.

Fortunately, since the physical symptoms of this illness are highly particular, it is simple to identify.

But what exactly causes it?

Aeromonas bacteria are the usual cause of these infections, the germs may enter the fish’s body through wounds caused by other fish or after an angelfish is attacked by another fish.

It’s also possible that your angelfish has fin rot if the quality of the water is poor or he or she is exposed to abrupt temperature changes, both of which decrease the fish’s natural resistance and raise the chance of fungal infection

What part of the body does this disease affect?

It usually affects the tail, but it can also strike the dorsal, pectoral, anal, and pelvic fins. It can also be seen accompanying other health issues such as dropsy.

Unfortunately, if not treated as soon as possible, the fish may succumb to bacterial infection and suffer from mobility and balance problems and may lead to death.

Factors That Make Fin and Tail Rot Occur

High pH: Angelfish are best suited to a low pH, slightly acidic water.

As ph goes up, the fish become more sensitive to stress.

Even fish that are used to a higher pH in their natural habitat will be stressed out when kept in an environment that is too high.

This can decrease their immunity and make them more susceptible to disease.

Water Too Cold: Coldwater increases the stickiness of the slime coat, which can clog up their pores.

It also slows down their metabolism, which decreases their ability to heal themselves.

Don’t forget that angelfish are happiest in water that is about 82 degrees Fahrenheit.

Damaged Fins or Tail: Even if you are an expert at netting your fish, accidents can happen.

Your angels may get injured during aggressive encounters with other angelfish.

It’s possible that your angles are injured as a result of an impact with a rock, so there are a variety of ways that they might be harmed!

Poor Water Quality: If the water in your tank is not properly filtered and/or aerated, you can bet that there is going to be a problem.

Fish waste and decaying food particles will foul the water. That’s never good for any fish!


a. Physical Signs of Fin Rot

In the early stages of fin rot, the fins’ edges will become milky and discolored.

Often, however, this transformation is so imperceptible that it goes unnoticed until the fins or tail begin to fray.

As the disease spreads, little pieces of the fins die and fall off, leaving a ragged edge.

Over time, the fins grow shorter and shorter as dead flesh sloughs off the afflicted fins

The injury may progress to the point where it looks like the fish’s skin has been burned and is peeling away.

b. Fin Rot Behavioral Signs

Your tropical fish will grow listless as a result of fin rot, also it causes the fish to become lethargic.

Don’t be surprised, your fish may also try to alleviate its discomfort by rubbing against the tank and other aquarium equipment. 

Additionally, if the fish is nipped and subsequently feels stressed or “bullied,” it will suffer from fin rot.

Overall, Fin rot does not cause any additional behavioral issues in your fish.

4. How To Prevent Fin Rot From Occurring

1. Purchasing Cautions

When purchasing tropical fish, keep an eye on the fins and tails very carefully.

Make sure you’re aware of how mild and severe fin rot looks like so you can thoroughly inspect each species of fish that catches your attention.

2. Separate the Infected Fish

As mentioned, Fin rot is caused by a fungus, so if you put an ill fish in with the others, the germs will spread to them as well.

Therefore, it’s very important to separate the fish as soon as you detect fin nipping marks.

3. Water Changes

Since the fish’s surroundings are a major cause of fin rot, make sure the aquarium water is changed on a regular basis

The frequency is determined by the size of the aquarium and the number of fish in it, although a 1-gallon uncycled water supply should be replaced every 3 days, while a 5-gallon tank every 7 days is recommended.

4. Clean the Aquarium

To disinfect the aquarium, clean it and all decors with boiling water.

When washing the sand, use a screen filter to remove food debris and other waste.

5. Feed the Fish Well

Keeping food in the aquarium for longer than 24 hours may cause it to go stale, making the water unfriendly for fish, and breeding grounds for bacteria; instead, feed your fish tiny amounts on a regular basis rather than sprinkling a large amount once and expecting it to last all day.

How to Treat Your Fish from Fin Rot

1. Remove any waste or debris from the bottom of the aquarium by siphoning out the gravel.

2. Perform a 25% water change on your fish tank

3. Check and track the water in your tank regularly. pH, temperature, chlorine, ammonia, nitrite, and nitrate levels should all be tested.

You may check for these at home with a water testing kit or go to your local Petbarn and get a free water test of your tank water.

4. If not all fish exhibit symptoms of fin rot, move the afflicted ones to a quarantine tank with a different net.

This is necessary to prevent the fin rot from spreading throughout the aquarium.

It’s also a good idea to relocate the fish if it’s being harassed by tankmates so it doesn’t get nipped again.

5. Treat the affected fish tank with Blue Planet’s Tri-Sulfa Tablets, API Stress Coat, Melafix, or a vet prescribed antibiotic.

6. During treatment, remove the active carbon from the filter.

7. To study whether the fin rot has stopped, check your fish every day.

If therapy is successful, the damaged fins and tail may gradually recover after a few weeks.

Antibiotics and Antifungals for Fin Rot

Other than fin rot, these antibiotics are used to treat a variety of bacterial and fungal diseases.

Some of these will damage the beneficial bacteria your fish need to live and require the aquarium to be recycled.

And it also may necessitate removing the charcoal filter since it might prevent the medication from being absorbed by the filter.

The owner may be instructed to perform water changes on a regular or frequent basis.

The water may be colored. As with all medicine, pay attention and follow the directions carefully.

1. Fungus Clear

Clear tablets of Jungle Fungus are an antibiotic and antifungal that treat fin rot.

There is no need to alter the water temperature with Fungus Clear.

Note: Use for a maximum of 8 to 10 days.

2. Furan-2

Furan-2 is a broad-spectrum antifungal that is effective against a wide range of bacterial infections, such as fin rot.

Note: It may kill plants.

3. Aquarium Salt

To cure fish diseases, aquarium salt is a frequent and beneficial component.

The tank temperature is slowly increased to 85 degrees after adding salt.

This salt will also aid in the formation of the protective slime coating on angels and other tropical fish.

How to use it?

Add 1 teaspoon of salt per gallon to the contaminated fish and quarantine them for a few days.

For more severe situations, use 2 to 2.5 teaspoons.

Add salt to the replacement water daily. Mix the salt in a large amount of water and wait for an hour. Repeat this procedure for 10 days.

Note: Using a quarantine tank is best as salt can kill plants and scaleless catfish such as corydoras and pictus. Tetras are also somewhat sensitive to salt.

Last Words

Fin rot is a common symptom of bacterial infections in freshwater fish and can be treated with antibiotics and antifungals.

It’s important to treat this illness since it can lead to secondary infections that could be deadly for your fish.

We hope you have found our information useful for you.

If you still have any questions, please share them with us in the comment section below.