i have just started the lawn maintenance on a large commercial property. their soil (or lack of) is almost all sand. i did a small test where i put thier soil in container with water, shook it up, and within seconds most of the soil settled. it turned out to be about 80% sand. this area of the state i'm told is the largest sand depoit east of the mississippi. right now they have weeds. i have read about topdressing, which is not being practiced in this area. from what i have read a good compost would help re-establish this lawn. i'm looking for suggestions. is spring a good time to topdress, should i aerate? overseed? and in what order? and what about a fert. program? i have never delt with such sandy soil, any help would be great thanks.