My contractor used about 16 lbs/1000 Turf type tall fesce due to extremly sandy soils on my new home. He didn't expect but about 50% to germintate or survive, but it all must have. Grass is very thick, and is only nice and green where the population is correct. Should I lightly power rake it to thin it out? Too much competition for nutrients I assume. Lawn is now 5 weeks old. Also, what is the best product going into late fall/early winter for high pH soils to reduce pH? Mine is 8.1. Power rake or hand thatching rake??