"BENIGN" Fe EDTA
30 g Ferric Sulfate
30 g di-Sodium EDTA
30 g Potassium Bromide
10 ml Sulfuric Acid (Conc.)
One litre water
or
30 g Ferric Sodium EDTA
30 g Potassium Bromide
30 g Sodium Bisulfate
One litre water
Bleaching time: One and a half times the time it takes to clear.
Temperature: 20C Agitation: Intermittent
One of the best "Cures for PBQ". Less hazardous to work with than the dreaded PBQ. Either version of the recipe gives the same result, the choice depending on the availibility of the ingredients. Check market prices for the Ferric Sodium EDTA, it can be less expensive to make it in solution by combining Ferric Sulfate with di-Sodium EDTA. Can use Sulfuric Acid or Sodium Bisulfate in either recipe as a buffer.
Shelf life: Leaving the solution exposed to air (uncovered tray) will extend the lifetime of the oxidizer. It has run its useful course when it takes very long to completely clear, like over 5 minutes.