Just another suggestion on Organics. Corn Gluten is a wonderful organic pre emergant it will also help with FA blooms in the pond. Try local farm stores or ganden centers. Try dirtdoctor.com for more organic information for the lawn. I am not sure on the timing in your area, but north central Texas timming is now until first of March.
Just a side note most chemical weed and feed products contain some not so good chemicals.
