White Scuff On Head, Fish Darting

[newfishy]

well my red mm platy has a white scuff mark on her head. then I noticed a few other fish are darting around sometimes.

other then that everyone looks healthy and fine, water stats are
a 0
ni 0
na20
ph8

nothing new has been introduced at all.


its a 29 gallon with 8 platys and 2 guppys.

what gives?

 

[WILDER]

The white mark on the head does it look bleached out.
Any excess mucas been produced on there body or gills.
Does the body look pale.
Check the gills to see if there pale with excess mucas, or red and inflamed.