I am so incredibly disappointed in the filters life.
We were careful to do our research before buying. We checked the chart showing how long the filters would last. Decided that there was a good return and ordered the product. After less than 120 gallons we smelt this odd fish odor - not a mild one by any stretch of the imagination. Not only did it mean that we had to replace the filter massively prematurely, but it came with the added inconvenience that you have to wash the entire unit before reuse.  So in two months we've used 3 filters. At these prices there is no way that this is remotely nominal value. 
So DO NOT BUY THIS unless you want to sign up for getting a new filter every month.