Bullied discus showing signs of stress - possible white spots Ich or epistylis?

[Branch]

I introduced 6 new 2" discus to my tank last week, 5 were eating straight away and have settled perfectly but the 6th is bullied and hides in the top corner. Today I noticed two white spots on the bullied fish, the others are fine. Question; do I cull it and remove the risk to the others as they're not stressed?

[Iminit]

Pictures will help. I’d put into qt tank for awhile.

[Branch]

False alarm guys there were no spots on the bullied fish this morning, not sure what it was. Always better to be alert and preventative rather than wait for disaster. They were quarantined for 4 weeks but the tank was small and for some reason the fish didn't seem to suffer as much as it has in the show tank?