Both my sebae (the one in my avatar) and my LTA were bleached out petco refugees. (b4 I knew better)
Though it's not the best way too start, they can recover.
Good water and good light.
Don't stress the force feed, leave it alone.
They get alot of what they need from light.
I feed my fish mysis, and my nems always pull some in.
Try a silverside piece like once a week, but if it doesn't take it don't try to make it eat it.
With good light it can go a long time w/out spot feeding.
When it's healthy, 1-2 silvers a week.