I have been using this bleach for a while, and ditching the blix from the c-41 powder kits. Alternative bleach for color negative motion picture process ECN-2. Water (32C) 900 ml Potassium ferricyanide (anh) 40 g Sodium bromide (anh) 25 g Water to make 1 l pH@25C=6.5 Bleach time is 3 minutes at 38C. Replenisher (SR-29R) Water (32C) 900 ml Potassium ferricyanide (anh) 55 g Sodium bromide (anh) 35 g Water to make 1 l pH@25C=8.0 Replenishment rate is 200 ml per 100 feet of film (or about 10 ml per roll). I just ran out of the sodium bromide an am wondering if there is a substitute for it?