Hi there, I have a fantail goldfish just over 6 months old. Recently he got what I believed to be finrot, so I treated him with erythromyocin for a week, performing the necessary water changes. I also replaced the filter and biowheel in my five gallon tank after the treatment. Now, about a week after the treatment, there is a white section of his tailfin with streaks of blood. At first this section was just white, but now its growing in size and there are more and more streak lines. Also I've noticed several spots on the side of the body (same as the section of the tail with problems) and the spots are sort of bloody and cloudy but hard to see. Fish is eating normally and pooping brown and a normal amount. Eating habits are normal. I'd love it if someone could help me diagnose poor Phillip here! I've attached a couple pictures. Hope to hear something soon!