7mag
You mention being surrounding by a housing community, is that correct? Realize if your watershed includes these pristine, green lawns you are probably some very nutrient rich runoff from their excess lawn fertilizer.
Unless you depend on this runoff to keep the pond full, you may consider creating burms to redirect the runoff from entering your pond, thus preventing excess nutrient loads to exist and your algae to flourish.
Sue and Cecil and Burger are all very excellent sources for info and know volumes more than I - really good advice they offer you should follow.