<a href=showthread.php?s=&postid=8215985#post8215985 target=_blank>Originally posted</a> by mbort
Thanks for all the information Russ. My proportional calculations were about right regarding the number of fills, just the accuracy was off on how much in each cartridge and number of lbs in a cubic foot (by about a factor of 2 on both).
I have found that, in my particular application, the performance of the resin has not decreased *significantly* after storing for about 12-15 months. Of course, it has probably lost some effectiveness, but I have not been able to measure it (my time interval between changes has remained about constant).