What I do is stick my hand in the sand all the way to the bottom, move it around through the whole tankto stir up as much as possible. For sand you should have 2x the recomended filtration, so right there your filters should pick up a lot of the debris that get stirred up. After doing this, wait 20 minutes for the debris/sand to settle and the filter to do its job. After this siphon out any debris that are sitting on top.