Also, if you have a cannister filter or diatom filter, set it up and run it for awhile. It'll filter out that fine sand that's floating around. A Magnum would work great. When I set up my tanks and end up with sand storms, I run either my HOB Magnum 250 or my Magnum 300 with the micron cartridges. Clears up any sand storm in an hour or two. While it's running, I also use a turkey baster to blow the sand that's settled on the rocks. Blow the sand back into the water column where it'll either settle or get sucked up and removed.