Just wanted to report back on a suggestion someone made earlier in this thread regarding the unmixed Part C developer. I too now store my Part C in the refrigerator, and it seems to be keeping very well. I'm using the original container it comes in, not displacing the air, and the lower temp seems to be keeping the degradation of that particular chemical at bay for at least a couple of months. The other chems (Part A / B, starter, bleach, fix, and stabilizer) all seem to keep just fine at room temp.