I think Jim advised against storing it in the fridge b/c of the light exposure it would get from people always opening & closing the fridge. From my understanding, the #1 killer of this solution is direct sunlight....and the #2 killer is any light at all....makes me wonder why they didn't put the solution in copletely opaque bottles vs. translucent ones.....and why they picked green bottles vs. brown....brown bottles tend to block UV rays while green bottles don't.