Swim has found that your wacker color was not dependant on total time but the amount of air it took up in the early hours of the rxn. if your uptake is lower in the early hours it will not change later. Swim had a rxn run for 8 hours using a stir bar, the color changed to a deep brown/red, but more brown than red, the rxn continued for 8 more hours with no further color change, was swims rxn done? is there something else swim could have done to make sure the rxn was finished? any help would be great.