My son is setting up a new fish tank and is using sand for the first time. He is concerned that any movement in his fish tank will cause cloudy water. Does the sand ever settle down, or is it always going to be cloudy. Anytime he wanst to do something in the tank like fix a plant or move a rock will it always get cloudy? Maybe he should not invested in sand. Can any one tell me what the trick is to keeping the sand settled. He wants to fix the problem before he puts fish in the tank.