I've used this filter for six years and never had a problem. Our two cats and small dog drink from the fountain daily. I change the filter once a month. Before putting in a new filter, I rinse it and then submerse it in cold water for five minutes.Other reviewers commented about a reduction in product quality, but I haven't noticed one.Also, there is an interesting DIY replacement review for this product to save some money. Not sure how many filters you'd have to make to recoup the cost, but it's worth the read.
Rating: [5 of 5 Stars!]