clamped fins betta

Clamped Fins in Betta Fish – Causes and Treatments

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Does your betta have clamped fins? If he does, you’ve come to the right place for helpful advice and our top tips on how to cure the problem!

Clamped fins in aquarium fishes are a clear sign that the fish are not healthy. However, there are lots of different reasons for your betta’s clamped fins.

Read this guide to find out why your betta has clamped fins and what steps you can take to help your poor pet.

What Are Clamped Fins?

The term “clamped fins” is used to describe when your betta fish pins its fins tightly against its body.

Some fish keepers have described the phenomenon as giving their betta the appearance of having been dipped in oil, leaving him unable to spread out his fins.

Why Does Your New Betta Have Clamped Fins?

There are lots of reasons for clamped fins among betta fish. Before you can successfully treat and cure the problem, you need to know why your betta has clamped fins.

So, you need to work through the potential reasons to figure out the cause. Once you know the reason for the problem, you can set about taking action to remedy it and help your betta buddy.


Bettas are highly sensitive to stress, and a very common cause for a betta’s clamped fins is that the fish is stressed out.

There are many potential causes of stress. A new betta fish has endured being transported from his breeder’s location via the shipping company to the pet store. From the pet store, your pet has been moved again to his new home with you.

Throughout that time, your betta has experienced different water conditions, changes in food, and even different company if he was kept in a display tank with a few other fish or inverts.

Often, after a few days, once your new betta fish has settled into his new environment, he will relax, and the problem of clamped fins will disappear.

Poor Water Conditions

Despite their origins in rice paddies, ditches, and stagnant ponds, bettas are surprisingly sensitive to poor water quality.

So, your first action should be to check the water quality in your betta’s fish tank. The levels of ammonia and nitrite should be zero, and nitrates should be 20 ppm or less.

If those levels are too high, you must perform partial water changes to remove ammonia and nitrite from the water and dilute the levels of nitrates.

Use an aquarium vacuum cleaner to remove organic waste before it has a chance to decompose and pollute the tank.

Inspect your filter system and clean it to remove sludge and algae that might be clogging the media, preventing effective water flow through the system. If the filter media are heavily soiled, replace them.

Inappropriate Water Conditions

Bettas need particular water parameters in their habitat to thrive. If the water chemistry is not suitable, your betta won’t thrive, and a symptom of that could be clamped fins.

The pH levels in your betta fish tank should be between 6.5 and 7.5, with a water hardness of 3 to 4 dGH and 3 to 5 dKH.

Water Temperature

The ideal temperature for a betta tank is 78°F, although it can be anywhere between 76°F and 80°F.

The key to the temperature in a betta tank is that it remains constant. Fluctuations in temperature can induce a condition called temperature shock, which can be fatal to bettas.

In addition, betta fish need to breathe atmospheric air through their labyrinth organ, visiting the water’s surface regularly to do so.

The ambient air temperature in the room must be the same as that in the betta tank, or damage to the labyrinth organ can occur.

Aggressive Tank Mates

Male bettas have a reputation for being aggressive critters. That’s definitely true when it comes to other male bettas. If you keep two male betta fish together, the chances are that they will fight, probably to the death.

However, a male betta can live harmoniously in a community tank with a range of peaceful fish and invertebrates as tank mates.

That said, we recommend you avoid keeping large, aggressive fish with your betta, as it’s absolutely possible that your pet could be bullied.

Bullying can result in physical injuries and almost certainly causes stress, which can lead to your betta clamping his fins.

Better Alone

Bettas are intelligent fish that usually appreciate the company of a few peaceful fish and perhaps some shrimp or snails.

However, some bettas get very stressed in the company of other creatures and are much happier when kept alone. Again, the stress of having other fish in their space can cause the betta to clamp his fins.

Remember that wild betta fish are highly territorial, and, sometimes, the presence of any other living creature can bring out that quality in your captive pet betta. That’s especially the case if you have a nano tank for your betta pet.

If you want to keep your betta with a few other fish to add interest to the display, you’ll need a larger tank.

A larger space with plenty of decorations, dense planting, and an imaginative hardscape allows your betta to pick a territory to defend and patrol.

Even an aggressive betta fish can be happier and more chilled out in a larger tank, so that’s definitely worth a try.

Aging Bettas

Just like with senior people, elderly betta fish can suffer from a weakened immune system. That can stress your fish, leading to clamped fins.

Obviously, there’s not much you can do about an aging betta. However, by providing your fish with pristine, perfect water conditions and a high-quality, varied diet, you can help your pet to live out his full life expectancy.

As bettas grow older, their appearance changes. The fish typically lose their beautiful, shiny appearance, and their fins tend to curl up.

As your fish approaches its maximum life expectancy of two to four years, you’ll notice its fins beginning to fray and curl at the ends. That can make it look as though the betta’s fins are clamped.

Physical Defects

Although it doesn’t happen often, some highly inbred bettas are born with defective fins that naturally curl inwards.

Again, there’s nothing you can do about that other than give your fish the best living conditions and diet you can.


Almost any of the most common fish diseases that affect bettas can lead to your fish clamping its fins.

There are lots of other symptoms that accompany clamped fins, so you’ll need to observe your pet carefully to determine what disease he’s suffering from and treat it accordingly.

Popeye Disease (Exophthalmia)

Popeye disease has a variety of causes, including bacterial infection and physical injury.

The key symptoms of Popeye include one or both eyes bulging out of the fish’s head. Lethargy, loss of appetite, and clamped fins are all symptoms of Popeye disease, as well.

White Spot Disease

White Spot disease is also known as Ich or Ick and can cause a fish to clamp its fins.

Ich is regarded as a major fish illness and is one of the most common diseases that affect freshwater and marine fish.

The condition is caused by the Ichthypthirius multifiliis parasite. The parasite is present in most aquariums but only becomes a problem when fish are stressed, already diseased, or in very poor condition.

The main symptoms of Ich include lethargy, flashing or flicking against objects in the tank, clamped fins, and a rash of tiny white spots over the affected fish’s fins, body, and gill covers.

Ich is treatable with over-the-counter medication, but it can be fatal if not treated correctly and promptly.

Velvet Disease

Velvet disease is more correctly known as Piscinoodinium pillulare. The condition can affect both freshwater and marine fish and is caused by an aquatic parasite.

The symptoms of this disease are similar to those of Ich, so the conditions are often confused. Fish with Velvet disease typically display the following symptoms:

  • clamped fins
  • flashing and rubbing on solid surfaces within their habitat
  • lethargy
  • light sensitivity
  • labored respiration
  • rapid breathing

The fish often develop a coating of yellow, white, or rust-colored powder across the body.

Look closely at your fish. If the dots are scattered across the body, the condition is probably Ich. However, if the dots are very close together and densely packed, your fish most likely has Velvet disease.

You need to treat Velvet quickly, as the parasite is very aggressive and spreads rapidly. Treat your affected fish in a quarantine tank with a recommended over-the-counter medication.

Take Action To Prevent Clamped Fins on Your Betta!

clamped fins betta

So, what can you do to prevent clamped fins in fish?

Well, there’s nothing you can do to prevent your betta fish from aging. However, most other causes of clamped fins can be prevented.


Stress in fish can shorten the creature’s lifespan and cause health issues. Common causes of stress in bettas include:

  • Keeping your fish in a tank that’s too small. A betta tank should be at least 5 gallons in capacity, ideally larger.
  • Overcrowded conditions are also highly stressful for your betta buddy, especially since bettas are territorial. Be sure to allow plenty of space for the betta and his tank mates.
  • Incorrect water parameters are a major cause of stress in bettas. Check the water parameters in your betta tank every week to ensure that the pH and water hardness are correct. The pH level should be in the range of 6.5 to 7.5, with a water hardness of 3 to 4 dGH and 3 to 5 dKH.In addition to providing your betta pet with the correct water chemistry, it’s essential that the water parameters remain stable. Fluctuations in water conditions will increase your fish’s stress levels considerably.
  • Incorrect water temperature will certainly stress your fish. The water temperature should be between 76°F to 80°F, with a sweet spot of 78°F.
  • Bettas are curious, intelligent fish that need lots to stimulate them mentally and physically. Provide your betta with lots of plants, decorations, pieces of driftwood, and toys to give your pet lots to keep him busy and interested. Many betta fish enjoy taking part in interactive training sessions and playing games with their owners. So, we strongly recommend that you buy a range of toys to entertain your pet.
  • Aggressive tank mates will certainly stress your betta buddy. Keep an eye on the interactions between all the residents in your betta tank, and be ready to remove any bullying companions.
  • Feeding an incorrect diet can cause your betta to become stressed. Give your betta fish a varied, high-protein diet that contains mostly meaty proteins in the form of frozen foods and live foods, provided you have a reliable supplier. Betta pellets should make up the remainder of your pet’s diet.

All those factors can result in a highly-stressed betta fish with clamped fins. However, bad water conditions are undoubtedly the primary cause of stress and disease in betta fish.

Betta Tank Maintenance

Maintain your fish tank properly by performing regular water changes of around 20% each week, using an aquarium vacuum cleaner to remove decomposing organic waste, such as fish poop and food debris.

Clean your filter unit and filter media every couple of weeks to remove any accumulations of sludge, which will block the filter and prevent it from working efficiently, potentially leading to an ammonia spike.

If you have live plants in your betta tank, trim away brown or dead leaves and broken stems.

Disease Prevention

All fish species are vulnerable to attack by various parasites that can cause clamping and curling of fins.

Keep diseases out of your tank by placing any new fish and plants in quarantine for at least two weeks before adding them to your main display tank.

It can also help to rinse plants and decorative items in an antibacterial and antiparasitic solution before putting them into your aquarium.

We recommend that you stick to feeding dry betta pellets and frozen meaty proteins rather than introducing live foods to the tank.

Live foods are a primary source of disease-causing parasites and bacteria, which you definitely don’t want to bring into your betta’s tank.


In this part of our guide, we answer some of the most commonly asked questions by concerned betta owners about clamped fins on bettas.

Q: Why Is My Betta Lethargic and Has Clamped Fins?

A: Bettas are tropical fish that need warm water to thrive. The ideal water temperature for betta fish is 75 to 80°F. If the water is too cold for your pet, his metabolism will slow down, and your fish will become lethargic.

Q: Why Does Your Betta Have Clamped Fins and Fading Color?

A: If your betta buddy starts to lose color from his fins, that’s usually due to a bacterial condition called fin rot. In fish with fin rot, the fins become ragged in appearance, and their color changes, often turning pale or black and losing their vibrant colors.

Q: Why Would a Betta Sorority Have Clamped Fins?

A: Often, female bettas in a sorority can all develop clamped fins at pretty much the same time. That’s usually due to an infection of some sort or a reaction to injuries sustained through squabbling and nipping.

You should also check the water quality to ensure that ammonia levels are not high. Poor water conditions are another reason your betta sorority might have clamped fins.

Final Thoughts

Did you enjoy our guide to why your betta has clamped fins? I hope the information we provided helped you to cure your betta buddy. If you found the article helpful, please share it!

There are many potential causes of clamped fins in bettas, including certain diseases. However, stress caused by a range of factors is a prime candidate for causing clamped fins in betta fish.

Keep your pet in a spacious tank with peaceful companions, feed your fish a correct, high-quality diet, and provide the betta with plenty of decorations, plants, and toys to keep him busy.

Ensure the water chemistry is correct and stable, and be sure to keep the tank topped up with clean water and clean the filter unit regularly.

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