Update: I hesitated for a while to use the skimmer sock because I'd read conflicting opinions on it here in the forum, but after a week or two of having clean water and STILL getting sediment on the bottom (even after shocking, vacuuming to waste, repeat), I decided to take the plunge, so to speak. I am now a skimmer sock convert - it works beautifully! Thanks again for everyone's advice and information...this new pool owner is completely grateful!!!