Product review (1 stars): Watch out for debris in the water before drinking - is the filter deteriorating after it gets wet?
If I could give zero stars I would. Did not contact seller as this was an old order.

I purchased these about a year ago and never used until recently so it is out of the normal return time period.

Not sure if this is typical but installed and flushed line about 3-4 gallons (7 pitchers of water) and was impressed - no detected carbon or other particles in water even on initial flush. Other filters that I had used had particles flow in first flush but not this one.

2 - 3 weeks later however I noticed substantial quantities of black and maybe brown string-like fibers and carbon particles. I believe the debris had been there but not noticed for some time.  In a 12 oz "cup" of water the bottom when settled was about 25% covered. I wish now that I had taken a photo.

I Installed the second one yesterday and again flushed the line 7 pitchers (3.5 gallons) and the water was clear. Earlier today about 12 hours later the water was clear but now about 24 hours after installation again there is significant amounts of stringy debris in the water.

The reasonable conclusion at least for these two units is that they were defective and once the filter material got wet began to break down quickly.

I'm less concerned about the carbon granules than the fabric or string elements in the debris unknown if they are "sharp".