Product review (2 stars): I simply object to the cost!
Who knows if they really work?  How many of us are that concerned with whether our ice cubes or chilled water is that much purer than tap water --- how do you wash your salad or fruits?  with Perrier?  But the reminder that you need to replace these always has my wife and daughter on my case that we'll all die of botulism if I don't replace them immediately.  So, with that understood, it's no wonder AquaFresh prices these are 20x what it costs them to make.