Is it okay if a betta is exposed to fin rot medication, even if it doesn't have fin rot?
I ask this because the other day in petco I found a really nice betta but it looked at if it had fin rot, and I really didn't have the money to afford him, meds, and a hospital tank.
It was one of these bettas.

I fell in love with him, but the black on the edges of his fins were really dark and didn't really fade into the yellow.