sore on guppy

[butterfly_koi]

I have a female guppy that has a wound near her tail, sure was like that when I bought her and didn't notice it until the drive home from the pet store. I raised the temp in the tank a little, started putting meds in once a day and today I put her in a breeder box for the day because my balloon Mollies pick the heck out of the sore, how long will it take for her to heal? Any ideas on what it could be?

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