Attached is a link to my photos on PhotoBucket

http://s1262.photobucket.com/albums/ii617/_holeshot1/

Thank You

If I'm right you do not have a problem. I think what's happening is the bluegrass has gone dormant (normal in extreme heat) and the fescue would like to. The KBG may have gone straight to dead because it really does not like high heat. In some places it is all dried out, dead, and gone.

The dead give away, so to speak, is in the corner where your sprinkler is and your foot is trying to peek into the picture. Concrete holds heat all night long and dries the soil much more there than elsewhere. That corner picture shows what I'm talking about. It is getting additional heat all night from two sides. I run a soaker hose adjacent to my asphalt driveway in the desert. That helps a lot.

Have you measured how much water your sprinklers put out? Get several tuna or cat food cans and run your sprinklers until the cans fill up. That is your starting point. Put some of the cans right next to the sprinklers, because some sprinklers throw water out and do not water adjacent to themselves.

Also how would you characterize your soil? Is is dune sand, sand with minor rubble (pea gravel), sand with considerable rubble, or anything else? Did they bring in anything besides sand/rubble when the house was built?

Once you know how much water your sprinkler is putting out, then you can work to manage it. The lawn needs an inch of water per week. In LV it might need to be watered 2x per week but for longer than you are watering now. Or if your soil cannot hold any moisture, it might need to be watered every day as the soil dries completely down several inches in your low humidity, heat, and wind. We'll know more after you check your system.

One of your close ups looked like a fungus but generally it looked dry. Fungus can cause it to look dry. Corn meal is a good start.

Your sand is good. You will never feel the need to aerate!! When it is full of pea gravel, then you have problems. Yours will hold moisture at least for a little while. Sandy soil can use all the organic fertilizer you can throw at it. Again, corn meal is a good start.

Did your pieces of sod knit into the sand? Can you pull up the sod anywhere? By now it should all be firmly stuck to the sand.

Topsoil is always a local product. Down here it is limestone rubble. In FL it is sand. You got your local version. I like sand. I order it any time I need fill. The best grass I have is on 6 inches of sand.

Once you use a chemical fungicide, then anything you do with corn meal is purely for the fertilizer effect. The anti fungal effect of corn meal depends on a very healthy population of fungi in the soil. If you use a fungicide, then you don't have that.

45 minutes 2x per day is 2 inches per day. That is very likely waaaaaay too freakin much. I would think that 45 minutes in the morning would be plenty to get it through to the next day - even in Las Vegas sand. Normal is considered to be 1 inch per week in the heat of summer but also normal is not considered 115 in the daytime/95 degrees at night/with 10% humidity.