I think I’ve heard that as well however I’ve personally never had any issues with it. Had it for around 7 months now and my fish seem to love it.Man, that’s what I was originally going to do….then I read so much stuff about the blasting sand containing pieces that were “possibly” harmful for fish. As in sharp pieces that could hurt their gills, etc.
Yes make sure you rinse it well or else it will be cloudy. Then just sprinkle it around until you’re happy with the color.So just rinse it super well and then carefully put some bowls of it in my tank and mix it around?