What's up with my grass?

[reverseration]

Hello all!
I've been lurking here for a short time. This will be my first post....I'll try to keep it short and sweet.
A little background: I renovated my small (~350sqft) front yard this april using the seedsuperstore sunny blend of KGB, rye, and fescue. It survived both a late snowfall and freeze and came out pretty nice if I do say so (well my neighbors all seem to think so too )
Now we're into the warm months and I know because its still baby grass I've gotta help it through its first summer so I've been keeping a very close eye on it. There seems to be a small section that didn't quite take off as well as the rest of it. It's covered for the most part but the grass isnt quite as thick or tall as the rest. I figured maybe it's just having some trouble establishing itself and will eventually catch up to the rest. This brings me to the reason for my post. Last week I came home on a particularly hot day and I noticed that that section looked really odd. It had an almost black haze to it and the blades themselves looked thinner. I figured maybe this was a sign of heat stress, it was 95 after all, so I got the hose out and gave it something to drink. That seemed to help a bit although it its been a few days without irrigation I can still notice the darker color.
Yesterday I was poking around and noticed what I've included pics of. The ends of some of the blades appear to be black/dead and pulling it apart you can definitely see this.
So....what's up with my grass? It's not brown so is it really from the heat? Is it a fungus?

[andy10917]

Compare what you see to images on Google of Pythium Blight.

If it is a match, get a bag of Scott's Disease-Ex and get on it ASAP. Pythium tends to spread along the lines that water flows - and will recur when it is hot and humid. Stay on it.

[reverseration]

well hmm...it seems like it may be the early stages of it. I'm so surprised since when I noticed it it seemed to be very dry conditions.
But I'll get right on it today...thanks for the help!

[reverseration]

should I also be lowering my HOC? It's currently 3-3.5"
I already plan on mowing it pretty short after the summer heat but will that help it dry out a bit to fight it?