Betta with a grazed side

and be careful about matching the temperature of the new water to the current tank temp. you don't want to put an injured fish under any more stress.
 
A little salt in the water will help keep it from getting infected also. About a teaspoon or a little less for ten gallons should do.

Joe
 
don't add salt. if the wound is deeper than you can see it could aggravate the tissues.

just do large water changes with fresh water. no additives other than dechlor, no salt. if there isn't any healing happening within a week then consider a treatment plan, but i think it should heal up with clean water.
 
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