The Grass Doctor

Could anybody give me the right recommendation for getting this lawn to grow good? This lawn was seeded last fall and the results are below (3 pics). (Tennessee zone 6b) The lawn has an irrigation sprinkler system. Want to know if it is better to put down pre-emergent now and wait 6 weeks or instead to go ahead focus on growing more grass. aerate, seed and fertilize really good again and to come after in summer time and spray for weeds with 24D or MSMA selective post emergent herbicides? This will kill even the crabgrass that came up as well ? I think somebody had told me their was even a granular post emergent chemical you could put down that would kill crabgrass after the event. http://i173.photobucket.com/albums/w65/cliffedwardsk/PicturesApril12007042.jpg http://i173.photobucket.com/albums/w65/cliffedwardsk/PicturesApril12007044.jpg http://i173.photobucket.com/albums/w65/cliffedwardsk/PicturesApril12007043.jpg DONT WANT CHEMLAWN. ACTUALLY , I AM THE LANDSCAPER.

Any really good lawn experts out there?? I have gotten so many different recommendations that it is driving me mad! I am a landscaper gardener, but am still new to the whole herbicide thing and how to come up with the perfect lawn. I have one lawn that is still new, kind of , was seeded good last fall, but still has bare areas and thin in places. I was thinking to just focus on seeding and fertilization instead of pre-emergent and then come back later in early fall and kill any weeds that came up over summer. the other is , i would say, 20% broadleaf weeds maybe less. the rest is fescue in shaded areas and bermuda in sunny areas. i have seeded , aerated , and fertilized this customer last spring and last fall and he wants to do it again this spring, but I am thinking maybe it would be better to put down a weed and feed (even though it has been in the 80's this last 2 weeks) , and thenspray his lawn 2-3 times over with 24D and maybe MSMA as well to get rid of his weeds and then seed and aerate him in the fal What would your recommend differently ?? why? HERE IS A PICTURE OF THE NEW LAWN I WAS TALKING ABOUT: http://i173.photobucket.com/albums/w65/cliffedwardsk/PicturesApril12007042.jpg http://i173.photobucket.com/albums/w65/cliffedwardsk/PicturesApril12007043.jpg