Do you see your pressure rising at all? If so, the filter is catching it and it will just take some time and patience. If not, you can try the DE trick-- take a cup or so of DE (just enough to raise your pressure by 1psi) and add it through the skimmer. First check your returns to see if it comes back through. If so, then you may have a problem with the filter that needs fixing. If not, then the DE will settle in the filter and help filter out smaller particles than sand can do alone.

Janet