Oh ok I was told by a guy in Houston that I got my high grade carbon that's really fine that I need to make sure it tumbles. And I'm having a problem with my gfo tumbling but my pellets do so I'm not sure what's up with that I have Even tried both in the same reactor with the same pump:(. The carbon I have is so fine it blows through my reactor and the. I have to scoop it out of my sump :( down side is we paid a lot of money for the carbon so I don't wanna waist it.