For those dealing with the initial cloudiness, what I did was rinse the sand thoroughly in small batches until it rinsed clear. It takes a bit more work but it's a lot more manageable than rinsing a whole bag or two at once. Also when I filled the tank, I dispersed the flow over a piece of wood or hardscape and with a watering can. Of course this is not realistic in a larger tank so diffusing the flow with a plastic bag or saucer helps. Be sure to fill it up slowly. Any remaining soot should be gone after a few hours with either a polishing pad or some filter floss. Hopefully that helps.