Help my Tiger Barb

Was it cut as in, an incision? Or cut completely off - It's missing?
More information.

Give us your tank size, and the other inhabitants of the tank
 
If it was bitten or torn adding some aquarium salt, or melafix may help him to heal faster. I would take him out of the tank and put him in a quarantine tank to ensure his ability to heal is not happered by other tank mates. Also just make sure the water stays as clean as possible while he heals.
 
Welcome to AC!
 
I would just do more frequent water changes to help your barb heal. Clean clean water is often underestimated. If you notice secondary issues, then medicate. Welcome to AC!
 
:welcome: Yes a few extra water changes will do wonders in most cases...:)
 
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