That link is better for selling products than it is for growing grass. If you want to grow great turf, there are three steps.
- Water deeply and infrequently. Deeply means at least an hour in every zone, all at once. Infrequently means monthly during the cool months and no more than weekly during the hottest part of summer. If your grass looks dry before the month/week is up, water longer next time. Deep watering grows deep, drought resistant roots. Infrequent watering allows the top layer of soil to dry completely which kills off many shallow rooted weeds and prevent new (weed) seeds from germinating.
- Mulch mow at the highest setting on your mower. Most grasses are the most dense when mowed tall. BERMUDA, centipede, and bent grasses are the most dense when mowed at the lowest setting on your mower. Dense grass shades out weeds and uses less water when tall. Dense grass feeds the deep roots you're developing in 1 above.
- Fertilize regularly. I fertilize 4 times per year using ordinary corn meal or ordinary alfalfa pellets (rabbit feed). Which fertilizer you use is much less important than numbers 1 and 2 above.
Notice that the first two elements are independent of whether you use organic or chemical fertilizers. If you do those you will be 90% of the way to a great lawn. The organic fertilizer IS NECESSARY if you want to eliminate the chemical insecticide that the chemical folks like to use. By using only organic materials on your yard you will see the return of birds, lizards, toads, and geckos. These critters are predators for bugs, slugs, snails, and caterpillars. When they come back you might see one or two bugs during the year but you will never again see an infestation of anything.
With two acres I would seriously consider landscaping to eliminate 1.5 acres of the turf and replace that with statuary, walkways, gazebo, rose garden, rock garden, picnic tables, barbecue, deck, patio, hedges, orchards, arbors, topiary, and other landscape elements that create interest in an otherwise boring expanse of water hogging turf.