They harvest from the ocean (at least some do) but it goes in their facilities for MONTHS, possibly YEARS, so they can determine if it is pathogen free or not. Also, some will place it in large tubs and put the tub in a dark room or cellar or something and not EVER open the door for about a year, possibly more, so that all diseases would be dead in the sand, and then they would put it in their systems for 6 months until it is VERY LIVE. Or, some places will take shells and LR and crush it so fine that it appears to be sand. Because after all, thats all sand is...crushed shell and LR.