That silt in the bagged sand is a real pain. I have some in my 20g long that has been there for years and if I work in the tank, I still get some silt stirred up. On the plus side, it does look good when everything has settled down. Mine at least is nice and white.
Just throw a hang on back power filter on the tank for a bit with some floss in it. That should suck a lot of it out of the water permanently. After it clears, just take the hob filter back off. You don't want the thing to go biological on you and end up being a nitrate factory.