I bought a bunch of bulk reagents from the SPS place a few years ago. I keep them in the fridge and only open to refill the smaller vials used day-to-day. I used to have a color photo lab as a hobby and the developing chemicals were a heck of a lot more sensitive than the pool reagents and using the same storage techniques the color stuff lasted indefinitely. Way past the recommended shelf life. And, the test was color comparison after developing/printing, new to old chemicals. Same with color paper and films.
Al