Black Sand Suitable For Cory's

[snazy]

I wouldn't go near anything volcanic, if I were you; I've just had to remove kilos of the stuff after it killed two BNs and a cory in one of my tanks. I might just have been unlucky, but better to be be on the safe side

 
Not unlucky I'd say. I've been dealing 6 months with missing barbels and bacterial issues in a cory fry tank that had black sand from volcanic origin. Problem showed up in full force two months after I put that sand in there. The sand is super fine but very abrasive and I never checked it prior to putting it because it said on the bag "suitable for corydoras"

 

[aaronc]

I decided not to risk it - and went with normal round sand.  
 
There were just too many conflicting reports for all dark sands
 
Wasn't prepared to risk the barbels for colour.