Review on CNZ Aquarium Filter Activated Ceramic by Shari Man

Very dusty coal that is difficult to clean. But that's not the real problem. The real problem is that I put the bag in a waterfall filter. The bag fell apart after 3 days. I woke up to find the water in my pond was dark black with a film on it making it look like an oil slick. A $50 lash and after 4 days my pond has almost recovered but the bottom and all the rocks remain covered in the remnants of black powdered charcoal.