Help With Ichy Datnoid

[Monolicious]

hi guys and gals,
I'm looking for same help here,My dat has been rubbing himself on the gravel of my tank for about a month,doesn't look like a full body rub more just his head or side of his face,There is no sign of white spot (ich) he seems to be doing this only when the lights go out,He is eating great taking about 6-8 white bait daily,just wondering if anyone had any ideas what it could be and possible treatments preferable treatments that won't upset my filtration.
He is the only fish in the tank to display this behavior,Please help

 

[mark93]

I have 4 tin foil barbs which i have had for 6 months they eat seem fine but flash tried everything can not stop them ..

i have two eheim pro3.
a resun cyclone filter which dos 2800 liters an hour .
a 160 gallon sump and they still flash.

they are in 550 gallon tank.

 

[deangelo]

up up my datnoid does the same other than the scratching he seems fine feeding, and being active