i think the question is if it's safe to use regular sand - meaning - play sand..? if so, that is debatable. i just upgraded tanks and did a lot of research on this and desided not to go with play sand. some ppl have luck with it in their tanks while others swear that they have terrible algae problems that they believe is due to the play sand. i went with a LS that i bought off ebay that i am EXTREMELY happy with. the seller was figisandman i believe. another user on these boards just purchased some of this sand as well and was very happy with his purchase. the sand was cheaper than buying aragonite from any lfs and basically the just a little more expensive than buying aragonite online.