My wife's employer designs, build and monitors municipal water treatment facilities - there is so much nutrient (fertilizer) run-off that they are hard-pressed to maintain clarity requirements because of the crush of algae growth.
Other than some lime to sweeten the soil, I too gave up on the lawn-control garbage feed to us by scotts, bayer, ortho and all the others years ago. Even after a #4 haircut (long), the 'weeds' - violets, clover, dandelion... recover very fast, and right after the mowing, other than the dark green of the neighbor's chemical lawns, mine (from a distance) doesn't look radically different.