1. According to the query of Shencaotang Health Network, methylene blue plays a bactericidal role through oxidation and reduction, and does little harm to new fish; Potassium permanganate has strong oxidation, which is harmful to new fish, and methylene blue is good.

2. The dosage and time of methylene blue are wide and easy to master; The dosage and time of potassium permanganate are accurate and difficult to master, and methylene blue is good.