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Betta fin rot & white gill lump. Why isn't my salt treatment working?

Updated On September 23rd, 2025

Pet's info: Fish | Unknown - Fish | Male | 0 lbs

I have been treating my betta fish for fin rot but I have noticed a small white lump growing on one side of his gills. I've been using AQ Salt as treatment for the past 3 days (2 tsp in 1-gallon tank with 100% water change daily) and noticed little improvement. I was wondering what the small lump could be and if I am doing something wrong with the treatment. He seems to be more lethargic either hiding or floating at the top of the tank. He also seems to be eating less

1 Answer

Most Helpful Answer

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Answered By Angel Alvarado, LVT

Licensed Veterinary Technician

Published on March 21st, 2017

Without an image or exam it can be difficult to differentiate between fungal or bacterial infection vs a developing tumor. Continue treating with AQ salt. It may take a few more days before you begin to see improvement. If the fin rot is minor, you can use 1 tsp /gal of AQ salt. Severe rot can be treated with aquarium salt at 2tsp/gal. Keep the water temp between 76-768 F. Turn off the light and filter to inhibit bacterial growth and decrease water current. Use treated or "aged" water daily for the water changes. A home test kit should be used to confirm good quality water is being used each time. Treat with AQ salt for a maximum of 10 days. His behavior may be due to low water temps or a chemical imbalance.

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