I noticed a white spot that sticks out on one of my neon tetras two days ago. The spot is a single large spot on his back . All other fish look ok. I have 3 neon tetras (including the one with the spot) 1 rummynose, 1 bronze cory, 1 panda cory and 2 minnows. Ammonia, Nitrite were tested yesterday and were at 0. I have started treating the tank today with King British WS3. I'm not sure if this problem is stress related as I bought a 64litre tank last monday and transfered all the fish from their 27litre tank to the bigger one about 6 days ago. The tetra was completely healthy before. All the fish are eating ok and swimming ok. I just want to know if I should continue using the whitespot treatment or is there something else wrong with him that I need to be treating him for.