Quote Originally Posted by Rudeofus View Post
I agree about the bleach and the final rinse but would advise caution with the fixer. The fixer is mostly Ammonium Thiosulfate which will go bad eventually, especially when mixed into a working solution. Unless you plan on using the kit within a few months, I recommend a procedure where unused concentrate is kept in a tightly sealed bottle (or several of them, depending on use), and working solution is only mixed as needed and used within a few weeks.

And yes, I have had fixer concentrate sulfur out on me in less than a year.
I usually keep fixer in concentrate and mix as needed. Generally though you want to buy in small enough quantities that you will use it up before it expires, this is tough when the smallest jug you can buy makes up 50 gallons, but for a 5L kit, you should be OK.