I have read much on the subject of rinsing sand......and my conclusion is......don't rinse it. To create a deep sand bed the fine dust particulate is especially helpful and goes a long way in creating the large surface area for the bacteria to cover. It takes a few days for the dust to settle but it will. Personally I didn't rinse my sand at all and it was clear within 24 hrs of me placing my live rock (though I had everything running for a week before that and I was sure it was never going to settle. But one I added my cured live rock and it cycled it was crystal clear.