Like many, I have to mail order my photo supplies. Since I have large quantities of bulk chemicals, I don't have to worry about running out of developer. However, I sometimes run out of rapid fixer, and I hate paying to ship rapid fixer through the mail anyway. I would like to buy a pail of sodium thiosulfate and use it to make fixer. Questions: Do I need any ingredients besides sodium thiosulfate to make fixer for both film and RC paper? What proportions do I mix the powder with water? Does anyone else use scratch-mixed sodium thiosulfate fixer? Is it economical to use it one-shot?