I think it would depend greatly on your climate. Would they be stored indoors? I store Aquatainers outside in a travel trailer. Temps here can range from about -10 F. to 110 F. I refill them in June and again in October, always adding 1 tsp bleach to each 7 gallon container. It has stored very well so far. I'd maybe try rotating at 1 month intervals at first, then gradually lengthening out to 3, or even 6 months depending on your results. I wouldn't bother with aereating (sp?) them if I were you.