i cleaned a large amount of sand in a 30gallon trash can. put the sand in fill up with water, swish it around. than pour out the cloudy water. repeat until the sand is clean and the water is clear. than stir the sand and see how long it takes to settle. if you think that its ready than go dump it in the tank, if it clouds up you can do a water change allthough it may just be a bacterial bloom bcuz of the new substrate
