Wed. Sep 18th, 2019

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Fin Rot

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severe fin rot
severe fin rot


Betta Fish fin rot is very common and easily cured.

The picture above shows a severe case of fin and tail rot.

Problem is that when you bought your betta fish in the pet shop, it is normally cramped inside a small plastic cup container.

The poor water parameters will cause the bacteria to wreak havoc on the betta fishtail and fin initially before going into serious diseases.

If you do not have regular water changes then this will probably lead into Cotton Wool Disease which is more severe.

You have to make sure that it fin or tail rot is not self-inflicted on biting or tearing due to boredom.

This is a bacterial infection.


Again as I mentioned over and over again.

Most of the betta fish diseases are caused by poor water parameters. Regular 25% weekly changes is a must and should be a part of your weekly household or office chores.

The bacteria is actually already present inside the betta fish tank. The bacteria attack the tail and fin of the betta fish if it is experiencing severe stress and weaken the immune system.

It is common sense that if your water is cloudy with recycled fish excrement s and rotten decayed food then this will cause high toxicity of ammonia, nitrite, and nitrate build up.

With these toxic elements inside your betta fish tank or community fish tank then, of course, the disease will strike anytime to your betta fish and its tank mates if you have a community fish tank setup.

If there are too many fish mates it will also accelerate the fin and tail rot since the water conditions will be very poor with too many excrement s cycling around with rotten food clouding the water.

Since if the immune system is weak then it is also possible that other diseases will be set for stage to attack your betta splendens and its fish mates.

If you see the fin or tail rot it may also be a sign that there might be aggravated by another disease which is already inside the betta fish.


betta fish anatomy
betta fish anatomy

There are various stages on the betta fish that you can visually see from the top, tail and bottom fins as you can see on the picture depicted above.

If you just ignore and do not make the immediate 25% water changes then it will lead to a severe case as depicted on the top page of this article.

There can be around three stages of fin rot on your betta fish.

Initial Fin Rot

You will notice that it is the beginning of fin rot. There are small whitish spots and tips on the fins of the betta fish.

And also some jagged fin edges that is not normal in appearance.

You will notice that when the betta fish swims and extends its fins, it will not be symmetrical anymore.

Middle Stage Fin Rot

You will notice that there is some white foam or cotton-like appearance on the fins.

A lot of the fins have receded. The fins are not is big as before and when the betta fish is swimming it needs some extra effort and strength to propel.

Severe Fin Rot

severe fin rot
severe fin rot

As depicted in the picture above again the tail and fins are almost gone.

The betta fish is struggling to swim. The body looks like to come out of a battlefield.

The whole body is inflamed and looks like it is injured.

You will notice that there will be cotton-like growth all over the body and especially where the former tail and fins are located.

In this condition, the betta fish will surely get infected with other types of the disease since the immune system is very susceptible to another onset of bacterial infection.


The treatment will depend on the stage of the fin and tail rot condition.

It is basically straightforward to treat the betta fish on the tail and fin rot ailment.

Initial Fin Rot Protocol

1. Do a 25% water change immediately. Make sure that the temperature is around 78-81 degrees Fahrenheit.

You have to make sure that the water heater is still working.

2. Try to clean the aquarium gravel with a siphon or hand vacuum to rid of excrement, rotten food, and other debris. Try to remove the filter and wash it with tap water to remove the excess food debris and fish waste.

You can reuse the filter since it is washable. Do not completely wash the filter too long on the tap water since you need the bacteria that was already established to be placed back into the fish tank. Just a quick rinse will be sufficient.

Wash all the decors on tap water. No soap of course.

3. If the fish tank is overcrowded then move some tank mates into another fish tank which of course needed to be cycled.

4. Observe the fish tank for about a week. If you have noticed that the fins are healing and the white spots on the tail and fins disappear then your betta fish is on its way to recovery.

5. Always ensure the have the regular water changes.

Middle Stage Fin Rot Protocol

1. Try to do 25% water changes every 2 to 3 days instead of every week. This will improve the water parameters on the fish tank.

2. Make sure again that the water heater is working since the betta fish natural habitat is in a tropical climate with 78-81 degrees Fahrenheit.

3. Add some aquarium salt to your fish tank. Around 1 teaspoon will be sufficient for your 10-gallon tank. You have to mix the aquarium salt in a glass of water first before adding it to the betta fish tank.

The aquarium salt will try to heal the wounds faster and relieves stress.

If you add the aquarium salt into the fish tank without dissolving it then it might burn your betta fish since it is too concentrated when entering the fish tank.

You have to do it gradually.

4. Do a 50% water change every day for about one week and observe. If the betta fish is not healing then follow step 3 above again for another week.

For sure by following the steps above your betta fish will surely show signs of healing.

Severe Fin Rot Protocol

1. If you see your betta fish that have cottons like growth all over its body and almost no tail and fins you have to do this immediately.

Prepare a 2-gallon hospital tank completely and be sure to cycle water before adding the betta fish.

Try to add an air pump for extra aeration on the hospital 2-gallon fish tank.

Try to make a 25% water change every 2 to 3 days and observe the betta fish.

2. On the main fish tank, you have to make a complete makeover or sanitize everything.

You have to clean all the decors, plants, gravel and filter.

Make sure to clean everything on hot tap water and lay it on direct sunlight including the fish tank until it is completely dry.

You should do this because it will kill all forms of disease it is inside the original fish tank.

3. Try to nitrogen cycle again on the main tank ensuring that everything is ready again for the betta fish.

You have to check the water parameters, ammonia, nitrite and nitrate levels on your main tank.

4. Add the recommended medicine on the hospital tank. Follow the instructions on the antibiotic: Maracyn II, Fungus Cure API Brand, Kanamycin and API Furan-2.

5. When you see that your betta fish is getting back its fins which is normally after 2 to 3 weeks then it is time to prepare its return into the original community fish tank.

You have to make sure that the community fish tank is not overcrowded or else the disease will be back.

Be sure that you do not put tank mates like tetras since they like to nip fins. The new fins of the betta fish is more delicate and thin.

Some tank mates might think it is food so you have to make sure to have very docile tank mates.

Preventive Maintenance

Is I have mentioned it is essential that you keep regular water changes.

The best method is to keep a plastic container small and big enough to scoop water on a daily basis and dump it on to your plants.

But doing a 25% water changes every week is good enough to maintain your betta fish community tank.

Try to rinse the filter every week or every month if you do not have time.

Also, try to avoid live foods to eliminate possible bacterial infection. If you wanted to give live food to your betta splendens then it is necessary that you have to culture it yourself ensuring that the food is clean and no bacterial or parasitic invasion will occur to your community fish tank.

Try to keep the portions small enough and just feed once a day or every other day will be sufficient,

aquaponics aquarium setup
aquaponics aquarium setup


aquaponics aquarium setup
aquaponics aquarium setup


In case if you opt to have an aquaponics setup then there will be less maintenance on your part since the plants will take care of the water condition for you,

All you need to do it just to add tap water when its evaporates and as needed.


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