I spend over $500 each year trying to treat my necrotic ring spot. I've tried Heritage, headway G, ring to green and several others. Strobe Pro G is my far the best product I've ever used for this disease. The lawn has completely filled in and looks healthy. You must fertilize as well and use proper watering recommendations. I wish I had some before and after pics. I know it will come back when the lawn gets stressed or in the fall, it always does. I plan to use this again each time it returns.