Centipede lawn in Alabama, with large swaths of yard with about 50-100% crabgrass. Additionally, last year I didn't water and had two large fairy rings or brown patches (perfect circular growth with discolored edges that grew to about 15' in diameter) which killed 25-50% of grass. This year, I applied Dimension preemerg in late Feb-early Mar. Then applied Heritage G Fungicide 3 times (about 4 weeks apart) after green up. I applied 1lb N per 1000 sqft (Scotts Weed and Feed 29-1-10 was all I could find with low P locally) after green up in May and have about 75% of yard with healthy centipede. I recently had spots in yard that had yellowing so applied chelated liquid iron about 1-2 weeks ago, which turned grass dark but is now returning to normal color after successive rains. I'd like to apply a post emerg to the areas of yard with crabgrass, as I think they will continue to dominate as I applied a preemerg and they still greened up (4 or 5 tillers). I've been hand pulling the seed shoots and bagging my lawn clippings. After reading this site and greendoc's posts, I plan on using Vantage applied at 0.5-.75 oz per gal per 1000 sqft. Is there any other things I should be doing to help the centipede out compete the crabgrass? We have had a fairly wet spring, so I have only been watering the portion of the yard which had fungal problems, and I overseeded this area with Tifblair centiped, and now I have some good looking, blue green centipede in this area, but also bare spots and areas dominated by crabgrass. Lastly, before applying Vantage, I read that I should prep the yard with a liquid fertilizer (1/2 lb of N from ammonium sulfate, 1/2 lb of K from potassium nitrate and soluble iron/manganese). I would like to buy the raw materials and mix myself, but I'm thinking that only commerical tank mixers can provide sufficient agitation for dilution. All I have is a Chapin Pro backpack sprayer, so should I just stick with granular fertilizer and spreader or is there a good premixed liquid fertilizer I can buy online? Thanks for any help.