Treating Betta Clamped fin (Sticky fin)

Posted by Pri | Betta, Illnesses, Maintenance | Sunday 25 July 2010 4:10 pm

Clamped fin, also known as sticky fin is very common in Betta. It is usually brought on by the stress of transportation and when introducing to a new tank. It can also happen unexpectedly to healthy Bettas that have been living in a tank for years.

This article is based on my experience with my own Betta named Alpha Betta. Alpha developed Clamped fin shortly after being introduced to his new home. The cause of the Clamped fin is unknown, but is likely to be down to the stress of being transported home from the pet store. Alpha has made a recovery and is now living happily in his tank.

Identifying Clamped fin


A healthy Betta should be active and swim around freely. Bettas also love flaring their fins, imagine a peacock when he is performing his courting display, his fins are fanned out. Similarly a Betta’s fins should generally be spread out. The image on the left shows Alpha before he developed clamped fin. As you can see his fins are fanned out and spread out away from his body.

Betta’s may close their fins occasionally when they are swimming, however the fins should not be held tightly close to the Betta’s body for a long period of time. If the fins are closed and the Betta doesn’t appear to be able to move them, it is highly likely that it is suffering from Clamped fin.

The images below shows Alpha Betta three days into his recovery period after developing clamped fin. After three days of treatment Alpha’s fins were still very close together, his bottom fins had ever so slightly spread out. At this point he had some control over his fins and had some movement.



When suffering from Clamped fin, the Betta’s movement may be reduced, Alpha chose to float in one area of the tank and hardly moved from that spot. He would occasionally swim to the surface for a breath of air, but would always return to the same spot. His general behaviour was to remain still in the one position. This is very likely to do with the fact that he did not have proper use of his fins, which made swimming very difficult for him.


Alpha is a very curious Betta and whenever he saw the hood come off his tank and a hand approach to feed him, he would swim to the surface to investigate. This stopped happening when he was ill and he remained in his chosen spot even during feeding time.

Whenever food floated past him, he would take either take a bite and then spit it out or just look at it and ignore it. I expected this when I gave him pellets, flakes and other forms of processed fish food, but he also turned his nose up to freeze dried blood worms, which he normally loves.

Alpha was not eating and in a desperate attempt to feed him I went out and got him some frozen live bloodworms. He did not complain about these and I now include frozen bloodworms in his weekly diet. Now that he is feeling better he is happy to eat freeze dried blood worms and food pellets.

Clamped fin is a sign of a sick or distressed Betta and should be treated as soon as possible. If left untreated may lead to death.

Treating Clamped fin

Inadequate tank setup

Unfortunately there is a lot of misguided information about keeping Betta. A lot of the information on the web suggests that it is ok to keep Betta’s in a 1 gallon tank without a filter or heater. Be warned, this information is actually incorrect and will reduce quality of life of your Betta.

I have even seen websites recommending jars or cups for Betta, as they believe that wild Betta survive in small puddles in rice paddies. This is simply cruel, and can cause a lot of stress for your Betta. The minimum tank size recommended for keeping a Betta is 5 gallons. Alpha Betta swims freely around his 7.5 gallon tank,  a 1 gallon container is simply too claustrophobic.

Betta are tropical fish from warmer climates, therefore an aquarium heater is required to maintain the water temperature at around 26 degrees Celsius. A Betta may clamp their fins if they are feeling cold, this is natures defence mechanism of preserving heat. The cause of your clamped fin may simply be down to the fact that the water is too cold for your Betta.

As I mentioned earlier clamped fin is usually the response of a sick fish. A very big cause of sick fish is poor water quality. This is especially the case if your tank doesn’t have a filter. No filter would mean that toxins can build up to a level which poisons your fish. This distresses the fish and makes the very prone to diseases.

Sorry if you have been victim of such poor advise, but you need to act quickly for the sake of your poor Betta. A minimum tank capacity of 5 gallons with a filter and heater should suffice. I would also recommend adding some extra aeration by the means of an airstone, this will especially be required if using medication.

Once your Betta has been properly housed, you should think about treating the Clamped fin.


Clamped fin may be the Betta’s response to an infection or disease. The first thing you need to do is take a very careful look at the Betta’s body under a light. You are looking for any abnormal bumps, lumps and marks. Tiny white spots indicate a disease called Ick (also known as Ich or White Spot), white patches indicate a fungus or rot and if it seems like the fins are disappearing or look like they have been eaten away, it may be fin rot. Also look out for parasites, tiny organisms that feed off your Betta and may move around on the surface of the Betta’s skin.

Spend some time inspecting the Betta to see if they show any sign of infection. If a particular disease can be identified, use medication that has been specifically designed to cure it. If not try Tetra General Tonic, which is designed to treat bacterial infections. Alpha was not showing any signs of a particular disease or infection, there were not spots or patches on his body, but he clearly had Clamped fin. I decided to use the General Tonic and it worked.

Now that you have your chosen medicine, you also need salt. I used Sea salt, but you may also use Kosher salt or Rock salt. The salt that you want to use should be sodium chloride (NaCl) and not contain any iodine or anti-caking agents. Sea salt is fine as long as it is natural. Aquarium salt is also a popular choice, but can be pricey. It is important to find out if it is ok to add salt with your chosen medicine first, from experience Sea salt and Tetra General Tonic are ok.

Isolate the Betta into a quarantine tank, it is easier to treat them this way and prevents any other fish kept in the same tank from distress. Also Bettas have a good salt tolerance, but other fish such as Neon tetras may not.

1. Remove 50% of the tank water – A water change should always be carried out if you discover a sick fish. This tries to eliminate as much as the free swimming parasites/bacteria as possible. It also removes toxins that stress out the fish and reduce their immune systems. I would recommend cleaning the gravel and removing 50% of the water using a gravel cleaning siphon. The next step is to prepare the clean medicated water that you are going to put into the tank.

2. Fill a bucket with half the capacity of your aquarium. The water should be a similar temperature to the water that is already in your tank. Next treat this water to remove chlorine and chloramines. I use Nutrafin AquaPlus Water Treatment, but there are many brands out there that do the same thing.

3. Now add 1 table spoon of salt per every 5 gallon of water that your tank normally contains. Give the water a good stir to ensure that all the salt has dissolved. This is important as large salt particles may burn the fish or irritate their skin.

4. Add the recommended dose of Tetra General Tonic and give it another good stir, this will turn your water a darkish green colour. Be careful not to spill the tonic on any surfaces or clothing. I would also suggest that you remove any ornaments or fixture from your tank as the medication will stain them. Also remove any carbon or zeolite filter media, as these will very quickly get rid of the medication.

5. If your tank doesn’t have one already, add an airstone and pump as the medication and high temperature will reduce the oxygen levels in the water.

6. Leave the mixture to settle for five minutes and then pour it into your tank. The tank water will now be a horrible green colour, however Tetra General Tonic is a good antibiotic and it’s good for your fish in the long run. The green colour will start to fade slowly over time.

7. Raise the temperature of the tank to 30 degrees Celsius. Do this gradually so you don’t shock the fish, an increase of 1 degree every hour should be ok.

8. The medication won’t work straight away, however you should see signs of improvement after 5 days. Alpha was able to move his fins again after 3 days, patience is a virtue. If after 7 days there are no signs of improvement, or your Betta still seems ill (staying in one place and not eating) then perform a re-dose with the General Tonic after doing another 50% water change.

9. Your Betta should slowly start to get their appetite back, at first they may only eat every two days and reject a lot of the food. Feed frozen live foods such as blood worms, which should help build their strength. At first the only thing that Alpha would eat were frozen blood worms, after a few days he was happy eating freeze dried blood worms and pellets, which are less messy.

10. Once treated your Betta should swim around normally and be able to flare his fins. The ends of the fins however may remain stuck together, even though the Betta is healthy. See image belows. Sadly I have read that they will stay like this for the rest of the Betta’s life, but I can’t say for certain. The Betta should be able to move their fins and not constantly hold them close together like a close umbrella.


11. If you are happy that your Betta is healthy, do a 30% water change, replace any ornaments and fixtures that you took out. Place the carbon and zeolite filter media back into the tank, this will take care of any remaining green colour in the water. Finally gradually reduce the temperature back to normal.

12. Salt is a good way to prevent diseases in your aquarium, Betta have a good tolerance to salt, if there are no other fish in the aquarium or if all fish have a good salt tolerance, it would be a good idea to maintain a concentration of 1 tablespoon of salt per every 5 gallons of water in your tank. It is always better to prevent a disease than to try fire fighting methods to cure it. But do check that the fish can tolerate salt, Plecs and Neons do not like salt. Salt may also increase the amount of unwanted substances in the tank and raise the acidity, so regular water changes is a must.

TIP: A good way to see a male Betta flare their fins is to trigger their dominance/mating display. They usually do this when they see other Bettas. To do this hold a mirror in front of the Betta, when he sees his reflection he will start his peacock like display by opening his gills and erecting his fins. The image below shows Alpha doing his stand-off pose. This is a cool display to watch and a good way to inspect the fins for any damage.

No Comments »

No comments yet.

RSS feed for comments on this post. TrackBack URI

Leave a comment