Product review (5 stars): Works better than expected & exactly as listed
Purchased these demineralization cartridges for our grandmother, to use in her humidifier that gets bad build-up & makes white dust.  We choose this product because these are suppose to fix those two problems.  We are extremely pleased with how well these work to fix both issues.

When these arrived we were surprised at the size of them, since we tried others that were much longer & bigger around as well.  These however work much better that the others we have tried & seem to last much longer also.  We have purchased these twice since & every time they work the same.

Before we left this review, we tried these cartridges out for months to make sure they worked as well as we thought they were working.  These are suppose to work for atleast one month, but we have left them in for over 3 to see if the build-up or white discharge came back...it took about 100 days until we noticed anything.  So we now change them 4 times a year or every 3 months.  This might vary for some by the size of the humidifier or the hardness of their water.

Pros:
Great quality, that lasts longer than expected
Reduces the white dust completely, no residue at all
&  Takes away all the water build-up, to save on extra humidifier cleaning

Cons:
None so far, and this is our third purchase

Overall we love these demineralization cartridges and would recommend them to anyone with build-up or white residue problems.  Our grandmother has recommended them to many of her friends & so have we.  This is a product that does exactly as it is listed to do.

Thank you for you time & interest in our review.  [...] -  Greg, Tina & Family