I'm setting up a new tank and thought I might use a black sand substrate; specifically, 40 lb of Carib-Sea black Hawaiian live sand. I would have just gone ahead without a second thought, but I recently saw a random comment on another thread here, which suggested that black sand might contain undetected pieces of metal. I didn't know what to make of this, but when I was getting the sand ready to use, I ran a few high power neodymium magnets through it, just to see what would happen. Much to my surprise, many or all of the black sand particles themselves seem to be quite magnetic! Here's one of the magnets, coated in clinging sand grains.
So, that's strange. Apparently black volcanic sand has a high iron content? Is there anything else to be concerned about? Any issues I should watch for as far as water chemistry?
So, that's strange. Apparently black volcanic sand has a high iron content? Is there anything else to be concerned about? Any issues I should watch for as far as water chemistry?