Go to www.kodak.com to find the technical data sheets for all these materials and follow the recommendations there.(posted 8594 days ago)D-76 is the most critical of those that you mention. I usually dilute it 1:1 and use it one-shot. Many people reuse fixer until it is exhausted. I prefer to use it once for the sake of consistency, but I also shoot T-Max, which exhausts fixer faster than other films.