I picked up a 55lb pail old Sodium Thiosulphate today, cost was $176 CAD. The product name is “Chlor Out” and is used in swimming pools and hot tubs to lower chlorine levels. I have used a variation of this product from an Amazon source, thou that cost more for 5 lbs. less product. I use this type of Sodium Thiosulphate as fixer for my Ambrotype work.
After mixing the fixer (hypo), I filter to remove any precipitate, then use it as normal, at a 30%-40% dilution. My old pool Sodium Thiosulfate stuff worked great. I am hoping this brand does as well. If it works for me, I will buy 3 or 4 pails next time. In my wet plate work, I go through a tone of hypo.
Note* From an online search.
Pool sodium thiosulfate, also known as "hypo," can be used in photography as a photographic fixer, meaning it dissolves the unexposed silver halide crystals on film or photographic paper, effectively making the image permanent by preventing further light exposure from affecting it; essentially, you can use pool sodium thiosulfate as a substitute for the dedicated photographic fixer solution, though it's important to check its purity and concentration before using it for photography.
