250 mg Tablet color varies per brand available. (Metronidazlole) also Flagyl  Anti-Canker medicine with a wide safety margin and safe to use during breeding, molting and during active periods. 1 tablet a day for 1 day.  Sometimes it's packaged as Fish Zole so pet shops can sell it over the counter.

Black head usually one tablet will also work 

25 count bottle.  EXTREME Limited supply!