Well now that is awfully nice to know! Yes, the little insert that came with it said clean "as needed" 
and my dealer said that the company recommends replacement after 2 tub-fulls.
No just hold on there a minute...
Anne, do your filters look like this:
Becuase if you have a standard, pleated filter you should be able to go the distance. If, however, you have some other type of filter, you may not be able to get that kind of performance out of it. Can you describe your filter to Terminator so we can all see a picture of it within a few minutes?
