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My betta fish is sick with fin rot and lethargic. How can I save him?

Updated On September 23rd, 2025

Pet's info: Fish | Betta | Male | unneutered

Hi; I have a betta I purchased about 3-4 months ago. He started to get fin rot, so i purchased Bettafix and did a 100% water change. However since yesterday (first day with bettafix) he is lethargic; all day today he was at the top (by the heater which keeps his tank at 78 F) but now hes at the bottom. Looking almost lifeless. Is there any way I can save him?

3 Answers

Most Helpful Answer

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Answered By Todd Cecil

Veterinarian

Published on February 26th, 2019

Thanks for reaching out about Flippy. A veterinary visit is highly recommended. Testing water quality for ph, ammonia, nitrites and nitrates, correcting any concerns. Water must be dechlorinated for several hours at least, prior to adding to the tank. Laying on the bottom could be a sign of a swim bladder infection and loss of buoyancy. Systemic antibiotics, not water additives, are recommended. Bettafix as a water additive does little for systemic infections. Good luck.

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    Answered By Dr. Dayna, DVM, CVA

    Veterinarian, Certified Veterinary Acupuncturist

    Published on October 7th, 2017

    The pet stores all have water additives you can use to help. I’ve used the melaleuca products in the past that have worked well. Continue to do frequent partial water changes and keep the water chemistry well balanced. Good luck!

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    Answered By Rebeccah Wood

    Licensed Veterinary Technician, Registered Laboratory Animal Technologist

    Published on August 13th, 2017

    Hello there! I'm sorry to hear that Moses has fin rot. Fin rot can be caused by either a bacteria, a fungus, or sometimes both. You're doing well by changing the water (though 20% once weekly should be sufficient - you don't want to remove too much of the tank's natural bacteria as they are what help keep the ammonia level low and maintain a natural homeostasis). Some fish experts suggest adding freshwater aquarium salt to the tank to help treat fungus at 1 teaspoon per gallon of water. Be sure to use salt made for freshwater aquariums - not table salt or marine salt. If this does not help, it may be bacterial, at which time you should contact an aquatic veterinarian or specialist for treatment options. Good luck, and I hope Moses recovers!

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HI my Betta fish male vail tail has a finrot so i cleaned all tank, i added stress zyme, water conditioner and fin rot treatment but now he is just lying at the bottom of the tank not movin. when i gently tap him with a fish net he will mkove a littl
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Thanks for reaching out about Norman and including photos. Test water quality for pH, ammonia, nitrite3 and nitrates. Correct problems as poor water conditions (high ammonia) with "new tank syndrome" can fray fins, cause gill damage (thereby swimming to surface to gulp air), and lethargy. If water parameters are good, a veterinary visit is needed to assess and provide a diagnostic/treatment plan. Good luck.
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My fish has fin rot and seems lethargic. He will just sit at the bottom of his tank or in his flower. He might also have a swim bladder issue. What can I do to fix him?
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Hello I have a beta fish I cleaned his tank the day before yesterday and conditioned the water then put him back in yesterday I noticed he was laying in the bottom on the tank he would swim around a little bit but then swim back to lay on he bottom.T
Thanks for reaching out about Stanley. First, test the water quality for pH, ammonia, nitrites and nitrates. Correct any problems. Laying on the bottom might be an indication of a swim bladder infection/fluid. These are commonly bacterial and systemic antibiotics required. A veterinary visit is needed to prescribe medications. Antibiotics added to the water are rarely absorbed, and are generally for skin infections, vis contact. Good luck.
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My betta fish is losing parts of her back tail, and I really need help. I've had her for about a year, and she has started to turn gray on her belly. I have already treated the tank for fin rot, but nothing happened. Is it a bacterial infection?
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Hi, I have a Betta fish and it is very low on energy level these days and it is losing his color.
Bettas are tropical fish. They need warm water. They do best between 78F and 80F.  Clean water is key in treating any infection. Check water chemistry using a home test kit or by submitting a water sample for testing. Aim for 0 ppm ammonia and nitrites with a 40ppm or less nitrate level. Perform partial water changes to stabilize chemistry and maintain water quality. Use only aged or conditioned water that is temperature matched to prevent stress or shock. A bit of aquarium salt (NOT table or Epsom salt) can be used as a general tonic to reduce stress, treat minor infection and aid in any recovery. Dissolve 1 teaspoon of salt per gallon of water in a cup of tank water and gently pour it into the tank. Treat for 10-14 days then reassess fin condition. More water changes can be done afterwards to reduce salinity.
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my male betta has moderate fin rot & the people at the pet store told me to put him in a quarantine tank with aquarium salt for 7-10 days. he’s lethargic, not eating, and not moving much and im very worried. ive had him in a quarantine tank for 2 day
Thanks for reaching out about Sami and including a photo. The water in the tank should be tested for pH, ammonia, nitrate and nitrate. Correct any abnormalities. Salt concentrations are usually not to the level to be anti-bacterial or anti-parasitic, but to decrease osmotic stress. If the water quality is good, a veterinarian should be visited for an examination and potential diagnostics. Antibiotics in the water, such as tetracycline, might help with topical concerns but is not absorbed systemically. Good luck.
Updated on September 24th, 2025
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Hi my betta has red patches at the edges of his fins. Also he can not use one of his front fins to swim. He can not swim straight.What should I do?
Poor water quality can cause stress which can lead to infection. Check the water chemistry and quality first. You can use a home test kit or submit a water sample for testing. The local Petco may do this for free or for a small fee. Aim for 0 ppm ammonia and nitrites with nitrates at 20ppm or less. Perform a partial water change (no more than 30% total volume at once) to stabilize chemistry and/or to improve water quality. Use only conditioned water that is temperature matched to prevent stress or shock. Bettas are tropical fish and do best between 78 F and 80 F. Add a teaspoon of plain aquarium salt (NOT table or Epsom salt) per gallon of water to the tank. Dissolve it first in a cup or two of tank water. The salt will reduce stress, improve gill function, treat minor infection and aid in recovery. Treat for 14 days then reassess fin condition. Perform partial water changes afterwards to decrease salinity. At the same time, withhold food for 2-3 days. Resume feeding bits of cooked,
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Petco Pet Education Center
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Hi, I own a crown tail betta fish, he is showing signs of discoloration, he is floating at the bottom of his bowl most of the time, and one of his fins is breaking. How can I treat him?
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Updated on September 24th, 2025
Petco Pet Education Center
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My male betta fish had been sitting at the bottom of my tank barely moving and breathing heavily. He won’t even come up for more air or for food. He has been doing this for the past 3 days. Help!
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Updated on September 24th, 2025
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