YEP looks like it to me but the dead give away would be the smell, scrape some off with a toothbrush and if the smell makes you want to barf, then yes its BGA. ethromycin is your best bet.
EDIT: if you have fry (baby cichlids) then I would do half doses twice a day instead of the full dose once a day
EDIT: if you have fry (baby cichlids) then I would do half doses twice a day instead of the full dose once a day