<a href=showthread.php?s=&postid=10022036#post10022036 target=_blank>Originally posted</a> by andbigdaddy2
I would return the sand
Some people use silica sand although it's usually not recommended.
If you go to the florida keyes the reefs are surrounded by calcium based sand, and this is the look that most reefers are going for.
Although if go to Fort Lauderdale and dive on the reefs, you'll find find grain silty silica sand surrounding the reefs.
There is also some reasoning that silica slowly dissolves into silicates that could potentially result in a diatom bloom. Although some glass is constantly dissolving as well, but I don't see people rushing to go acryllic.
Another reason is the buffering effect that Ca based sands would have that silica would not, but if you're PH drops that far that the buffering would kick in, you'd have bigger problems.
Also, there are lots of sand sifting critters that do better when the sand isn't as fine as normal silica sand. But, again, I found plenty of blennies living in the silica sand around Fort Lauderdale. Although with is much sand as my Blenny throws around in my tank, I'm glad it's not the silty variety.
With all the above said, some people routinely use silica based sand because it's much, much cheaper (or free), and they claim good results.
Also, I'd ignore the dire predictions of impending doom by getting something direct from the ocean or beach. It's really neat to figure out your local aquatic systems and I'd encourage you to do so.
Some people go nuts when you say you collected fresh ocean water instead of using a salt mix and predict imminant collapse of your tank (although the same people often don't bother to QT their fish). I'd refrain if I lived in a polluted, highly populated area, but for NE Florida beaches, I just don't buy the doom and gloom.
