If anything you should have raised the mower. Going that short would be one mistake. Watering every other day for hours is probably too much. Certainly it is too often and if your watering system is working at all, then you are overwatering the snot out of your yard. With that in mind I am going to suggest that you might have a fungal disease caused by the yard being continually soggy. I have a home in San Antonio and one much further out in the desert. As of this month I do not have a regular watering schedule yet. The desert house has received about 4 inches of rain this year but spaced just about perfectly. I have watered parts of the yard once or twice but most of the yard has not been under a sprinkler yet. In San Antonio we have received 15 inches of rain. We are just now getting ready to go to regular, once per week, watering. Everyone's watering situation is different, but not by much. There are about 10 different factors to consider, but it is much easier to look at the grass and let it tell you when it needs water. You'll see a darkening as the blades fold together. Then it is time to give it a full inch of water more or less. Whether it is more or less depends on how long the grass goes before it needs water again. If the temps are above 90 then you should water once per week. If the temps are between 80 and 90 you should be able to go every 2 weeks between watering. If your grass tells you it needs water before the suggested time is up, then water immediately but water for a longer duration. Soon you will get into a groove with that. The only thing worse than watering every other day for hours would be watering every day for hours. Even watering every other day for 10 minutes is bad. It is much better to apply a full inch all at one time and then let the surface of the soil completely dry out before watering again. Back way off on the watering, as much as Mother Nature will let you. Then see if the spots get better or worse. Assuming they get worse you will need a fungicide to stop the spread. I am not a fungicide kind of guy but I have seen Immunox mentioned by Tiemco on this forum. Read the label carefully for the weather conditions needed for proper application. About 3 weeks after you are convinced the fungus is gone, then you should reintroduce the beneficial fungi back to your soil which the fungicide knocked out. The best way to do that is with compost applied at no more than 1 cubic yard per 1,000 square feet. That is a fairly light dusting. After you apply it as evenly as possible, use a push broom to sweep it off the grass blades and lift them up out of the compost. Don't apply lime unless you have a soil test that tells you it is deficient. There are two kinds of lime so the test needs to tell you which one to use and how much.

Looks like dollar spot to me. Symptoms/Signs: Small (1-3 inches diameter), brown to straw-colored patches of dead grass will develop. Irregular, light tan lesions with distinct brown borders will be present on the leaves at the outside edge of the patch. The small individual patches do not expand in size, but as the number of patches increase, they may merge together to form larger patches. White, cottony mycelia may be observed in early morning hours when dew is present. Below is a great link for Florida Lawns, You'll want to bookmark this one. LOOK in the disease management sections for pics and control of Dollar Spot, Gray Leaf Spot, and Cercospora Leaf Spot. All of these have similar characteristics, but different control options, so be sure you know which disease you have before any treatment. Your best bet would be to take a few of the effected blades and roots to your local extension office and have them diagnose your problem for FREE. Here is a link that might be useful: University of FLORIDA

Why do people post things in the picture gallery without pictures? This place doesn't get many visitors in the first place. Why don't you post to the regular Trees Forum AND provide pictures?

I'm doing a Logan Labs test next summer, the last two I've been using the local extension. In that area of the lawn I have 1-4 inches of nice brown soil (what I get tested), and then a sharp division into red clay. It's not at the surface, but it's not far down, and the dividing line is stark. You can literally make a pot out of it. When it's wet it comes out in huge, softball size clumps when I dig with the shovel, big soft plastic sticky clay. When its dry, it's nearly impossible to dig in, it's more excavating a hole in terra cotta by slowly scraping away the sides. Dry you can't dig a shovel in for love or money. Yes, I would like to level the lawn. Right now I have a 2 year old and a new baby so I'm trying to stick to smaller projects. I've been wondering about the disease as well. That soil there is almost always quite dry, at least at the surface. There is no puddling once the rain stops - it's on a grade. Now that the grass is so thin the topsoil layer is getting "grainy" and dusty and I'm worried about it being eroded away. Weeds also do not grow well there. I have an ongoing oxalis infestation in the yard, and they have a hard time growing in that spot. They will live there, but they won't flourish like elsewhere, they get dry and brittle. Other weeds don't really bother colonizing the location. I'd like to figure out if it has any other cultural problems beyond losing water to the trees / downhill. If you have any other suggestions or cultural questions, please let me know! Here are the last two state lab tests I've had done on the lawn. Samples were taken from the whole lawn, though next year I may submit some from just in that location. Organic matter is low. I mulch mow and mow in whatever (not many) leaves fall. I did a bag of Milorganite this year, and 25 lbs of cracked corn / 1000. I'll throw a few organic feedings at it next year as well.