The problem I found with Black Diamond Black Sand is it can be very difficult to tell what you are actually getting. I ordered the "coarse" from Tractor Supply and they sent me bags of what appear to be fine dust and not what people show in their tanks. While the bag itself had checkboxes for checking the grit/nozzle size, none of them were checked, so Black Diamond itself does not bother writing or indicating on their bags what grit their product is. I took them back and they said that is the only bag made now, that they used to have red and black but just one of them now. It was confusing and you'll notice in a lot of posts people complain of weeks of clouding after using Black Diamond probably due to getting the wrong grit. I decided not to take a chance and went with Seachem Black Sand and have not looked back. Despite the $150, I like the peace of mind of knowing what I got. I'm glad some folks figured it out and got it to work for them, but not worth the risk IMO.