I would say if lots of big water changes haven't helped (clean water can do wonders!) it's probably time for an antibiotic. Red streaks say bacterial infection to me.
If you're in the US you have a few choices. I'm not sure which I'd go with, maybe like Maracyn 1 & 2 at the same time. If you not in the US your options are very few in lots of places...Where, in general, do you live?