Betta Fish Fin Rot - Help Treating


New member
Hello- I believe my betta fish has fin rot because the edges of their fin is jagged and torn. There are not any other tank mates other than some shrimp. However I am new at fish tanks and I let my tank balance get out of control due to over feeding. I have a 10 gal tank. I've been fighting getting back to a 0 Nitrite and near 0 Nitrate with daily water changes of about 30% for a week now.

I'm trying to treat my betta with aquarium salt (1tsp per 1 gal) and I have a 2 gal quarantine tank. However after 24hours in the QT with the Aquarium Salt my fish looked near death. Prior to going into the QT tank they would swim and zip around their tank. However in the QT tank they would just lay at the bottom and not move or eat.

After 24hrs I was afraid I was going to kill my betta so instead of doing a 100% water change and reapplying the aquarium salt I just moved my betta back into their normal tank.

Please help- am I being over sensitive and need to stick with the aquarium salt and QT tank for 3-4 more days?
Has anyone had their betta absolutely hate aquarium salt?
Do I even need aquarium salt? Will the fin rot just go away on it's own with frequent water changes?

Andy W.

New member
First question for you, is it freshwater salt or saltwater salt?

Second question (and most important): water parameters?
Ammonia at 0? If not, your tank is not cycled.
Nitrite at 0? If not, your tank is not completely cycled.
Nitrate at 0? If not, not a dealbreaker.

Nitrate is the 'end product' of the nitrogen cycle we cultivate in our aquariums, and while it is toxic to fish, it is not nearly as toxic as ammonia or nitrite, only after levels become higher than 20-40ppm depending on who you talk to. Most aquarists consider 20ppm a target, and if you can reduce it lower than that, wonderful. Water changes are the main way to reduce nitrate.

From your description, your betta has a bacterial infection causing the fin rot, rather than fungal. Betta are especially vulnerable due to poor water conditions, such as what they are kept in while at stores. You compounded your issue with letting your tank get out of control via overfeeding.
The solution is already in process, you have started doing daily water changes, and hopefully maintained a stricter diet so less food goes uneaten and decays.

The best solution is to maintain proper water conditions, which you seem to be back on the path to doing. Whether additional treatment is needed is tricky. I would ask myself how long I have had the fish, to determine if it was preexisting and stress caused the breakout; I would also consider the other occupants of the tank. Most fin rot can be recovered from, as long as it is the extremeties of the fins. Think of it like hair, where if it hasn't damaged the scalp it will grow back. If you are concerned about fin loss due to agressive fin rot, antibiotics will be most effective (with your jagged description it appears to be Pseudomonas fluorescens.)

As far as your salt question, you are using the salt for it's antiseptic properties to treat the symptoms (which fin rot is, symptom of the infection).
The type of salt you use matters, but also the conditions in the hospital tank. 2 gallons is not a huge amount of water, but if the water temperature is significantly different from the main tank it could result in the behavior you mentioned. An airstone (or air driven sponge filter) are also useful to maintain oxygen levels. It is usually counterproductive to feed fish in a hospital tank, as they can go a day or two without eating if properly fed. Retrying the salt bath is a complicated question, but the fin damage will regenerate over time as long as the damage has not reached the body of the fish.

1. check your water parameters, make sure the tank is completely cycled and ph is appropriate.
2. maintain current regimen of water changes, until conditions are to your satisfaction.
3. if you are concerned the infection is too agressive to be recovered from in time, apply antibiotics.


New member
From what I’ve seen, warm, clean water will do wonders for bettas. What temperature are you keeping the tank at? I say keep them in their normal tank, and keep up with water changed to keep ammonia and nitrite as close to 0 as possible. If you decide to go the medication route, avoid anything with “betta” or “fix” in the name; I’ve heard those can do more harm than good.

If you can, try to upload a picture. I know sometimes torn fins can get mistaken for fin rot. Do you have any plastic decor in the tank?

best of luck!


New member
Thank you all for your replies!
Freshwater Fish
Nitrate levels are now around 10ppm
Nitrite levels are now at 0
Ammonia is at 0

Before Nitrate was as high as 75ppm
and Nitrites were at 5
- Again this was totally self inflicted as a novice to keeping fish.

I keep the normal tank at 78 degrees however I did not have a heater or filter for the hospital tank. So I'm assuming the hospital tank would be closer to room temperature at around 73-74 degrees.

I was using aquarium salt.

I do have plastic decor in the normal tank. I'm working on getting some pictures posted.

Andy W.

New member
Nice, it sounds like your nitrogen cycle is back in working order, and the betta is on the road to recovery.

The temperature change certainly could have added to the stress of the fish resulting in the lethargic behavior you witnessed, although the recommendation to treat fin rot of your example is to lower the temperature, to delay the growth of bacteria causing the fin rot.

It sounds like you did everything correctly in response to a situation that got neglected for a bit, but I would presume a large percentage of aquarists have had that happen in their time in the hobby.