I agree, I'd try shortening the elastic first if it seems a bit loose. I've been using ours for over a year now (in a large rotation, but they still get a lot of use) and haven't replaced them yet. I can tell it has stretched a bit, but I'm going to wait awhile before I swap them out. They fit so well and we don't have any leaks.
You'll probably just want to see how much give is in the elastic, especially once it's tightened. Is it still sealing around the legs? Does it still spring back if you pull on it?
How long the elastic lasts will really depend on a lot of factors... how often they're used, your washing and drying routine, etc.
I've heard that attaching a safety pin to the end of the elastic can make it easier to thread through, though! I haven't tried it but I will when it's time to replace.
Mommy to Grant (July 2010) and Greta (July 2012)
I purged 2,920 items in 2012! Working on 2,013 items for 2013.
Last edited by wordbox; 08-12-2011 at 10:52 PM.