Just because I didn't see much about this substrate in my searches, I thought I'd give my initial thoughts about it. Buffers to a pH of 6.5
1) It's a bit expensive, but I didn't need very much so it didn't bother me. Might not be my first choice if I was doing a whole rack of tanks though.
2) It comes in two grain sizes. They are both nice and black. I got the Micro grain size and it looks coooool!
3) It looks like the grains will be the perfect size for the shrimpies to play with, but it's also super floaty and light, and so very tough to plant it. Even positioning rocks in it was a bit tricky because with a very light touch everything moves, and slides around. But did I mention it looked cool?
I don't have any shrimp in there yet, so I'll have to wait to update with how they seem to like it next week.
Here are some pictures.
Has anyone use the bigger grain size? Wondering if it is just as floaty and light.