Instruct: Classify Amazon reviews into positive or negative sentiment
Query: What's with the Black Particles???

The water certainly tastes great and you can find these just about anywhere. Also, they are easy to change and the pitchers are well-designed. But, what's with the black particles? (Either carbon or coal?) They are frequently in the draining basin, but if you attempt to pour water while this basin still has any amount of water in it, you can get these in your glass. I don't understand why this is so difficult to fix but it doesn't seem from other reviews that Brita is too interested in doing so.