Now I'm keeping her in a 20 inch tank. There were 2 female guppy in this tank (I separated them from the main tank because they were pregnant). At first she was bitten by another fish. But after a while it started not biting, but still biting a bit. The tank is quite wide and has aquatic plants. So I didn't separate them. How should I treat her? (I'm in Thailand, maybe not able to buy medicines from abroad, but you can recommend them first in case I can find them.)