I just put it in a 5gallon bucket and fill it with water and stir it around. Let the dust and small sand particles overflow out of the bucket, Stir it around to speed the process, Thats at least how i did it.. Thats for new sand, as for sand alrdy in the tank, Its best to just use a siphon to suck up the nasty stuff off the top of the sand, You will suck up a little sand, really no preventing that. You can also stir it around in the tank and proform a water change right after to take all that junk out... Might not be the best idea but it does work