well I had to wash my sand for a couple of hours before it ran clear, and even the water on top once it settled was lovely and clear, but once I put it it the tank, it went murky, but cleared in about 1 and a half days.. So I guess even if the water runs clear when you wash it, no matter how long you wash it for, it will still go murky in the tank. It is weird, and because I am curious, does anyone know why it goes murky? or is it just the angle we look at it from, as in when we wash it we are looking down on it, but once in the tank, we are looking through it so to speak... smiles. Therefore the particles not normally seen because we are looking down through to sand on the bottom can be seen when we don't have the sand as a background. Hope that made sense.... smiles