Flicking Against Objects?

[taxicab823]

so i have 1 fish that will contantly flick against objects but some of my other fish never do it and others will barely do it. i'm figuring it's either ich or some sort of parasite. however there are no white spots on them and all the fish look perfectly healthy and they all eat fine. my tank size is 30
temp is 77
ammonia-0
nitrite- 0
nitrate- 10
ph-7

current fish
3 cherry barbs
3 checker barbs
3 zebra danios
1 yellow panchax
1 widemoth pleco

i've been reading online and to me it sounds like it's either ich or gill flukes, anyone have first hand experience and what would it be better to treat first?

any help is appreciated.

 

[WILDER]

Do the fish have pale gills with excess slime, or red inflamed gills.
Do the fish have an apaque body with excess slime.
Any fish darting around the tank or erratic swimming.
Do the fish swim in a jerky movement.
Any fish gone thin.
Any sores on the body of the fish.
Any fish spitting food out.
Laboured breathing, or gasping at surface of tank.