Product review (2 stars): Residual taste is a problem. I had hoped it wasn't.... but it is
So the residual taste issue is something I was worried about based on the reviews and its certainly a valid concern. I have been using this off and on for about a month and have used well beyond 15 gallons, most of which was drained. There is still some residual taste. For people who continue to have this residue after the suggested initial waste, double it. Triple it if you have to.

Sadly I'm barely using this and relying on my other filters.