Sodium Sulfite as mentioned should work. Sodium Carbonate does work....use half a teaspoon to 1 liter water. 3 to 5 minutes post fix ( don't rinse ) with agitation every 30 sec's. It has been suggested to me using this as a pre-soak will also work...I've not tried it this way though. Note: A Kodak rep informed me it is a speed enhancing dye !!!.(posted 8878 days ago)