Best way to keep your wood floors clean is to use a canister vacuum with brush wand to vacuum sand and dust.  Use manufacturer recommended cleaning product.  Some of these products can leave a residue and build up.  If you do not have a wood floor recommended cleaning product.  You may mix a 1/2 cut of white vinegar in one gallon of water.  Mist the floor with the solution and wipe off with a cotton cloth or towel. Be carefull with adjacent marble surfaces, the vinegar solution can damage the shine on marble.