Pictures are usually needed but I think you have identified the culprit - fungal disease. I live in San Antonio, TX. I believe we have a similar issue with chemical fungicides. They must be applied when the temperature is not going to be above 80 degrees and no rain or irrigation for 7 days. Well, when is that??? January 3rd??? I had given up on finding a solution when I heard a guy on the radio suggest using ordinary corn meal on plants with fungal disease. I tried it on a rose plant and it was cured in a week. Nobody was more surprised than I was. Next week I listened to that radio guy for 3 hours. That day I went out and bought 50 pounds of corn meal at my local feed store. The rest is history. Since then I have never been afraid of a fungal disease. I have watched my garden carefully and have even identified the cause of my fungal disease issues. It is my wife leaving garden clippings on the lawn for a few days. Dew forms and the normal air flow is choked off by the pile of clippings. She had one favorite place to put the clippings so I just pretreated it with corn meal every spring. Now I have her putting them in the compost pile or on the concrete until they can be disposed of. The application rate to get rid of disease is 20 pounds per 1,000 square feet. You should apply to the entire lawn so you don't end up with green spots where you applied it. Corn meal is an organic fertilizer, too.

Having said that and rereading your original message, if you have already used a fungicide, then corn meal may not work. Corn meal relies on the fungal health of the soil. If you have sprayed a fungicide then you have no fungal health left. You might want to apply compost first. Give the compost 2 weeks to work and then use corn meal. Then give the corn meal 3 full weeks to work. I would reapply after 3 weeks whether you have seen progress or not. The second app at the third week will thrive on the back of the first dose and should supercharge the antifungal effect.

Most people wonder how corn meal works to kill fungus. The original TAMU work showed that corn meal contributes to the growth of the Trichoderma fungus. Trichoderma is a naturally occurring, predatory fungus that feeds on the cellular structure of other fungi. Normal soil has Trichoderma but not in high populations. Corn meal is decomposed by another fungus that multiplies the population of Trichoderma.

Thank you kindly for your reponse and insight. I do not think I have much thatch but to be safe, I purchased and used a thatch rake to hopefully get some air circulation amongst the grass.

I will try the Corn Meal approach.

I did notice when I use to make a homemade tonic of soda, ammonia, lemon scented antibacterial dish soap and cheap beer that my lawn was much healthier looking. I hadn't used that tonic application in years. Do you think that home remedy may help again?

Here is a link that might be useful: Pictures of Brandon's Lawn

Great pix. Close up shows brown water drop shaped spots on the blades. That is the fungus.

Use the Jerry Baker tonic but make it baby shampoo instead of antibacterial anything. You want to keep the bacteria in your soil, not kill them. Don't think of that tonic as a fertilizer. You still need pounds of fertilizer to feed the lawn. Ounces of liquids can't equate to pounds of fertilizer.