It certainly appears to be a fungal disease from your pics and I wouldn't expect it to get any better, you will probably have disease issues all summer. (I am assuming you have tall fescue, as that's what it looks like) New grass is very susceptible to all sorts of fungal disease, more so than established turf. As your humidity levels rise, and the nights stay in the 70's and 80's fungal diseases are going to be even more virulent. What can you do? Well fungicides can be used, but the good ones are expensive, don't last very long, and aren't exactly non toxic. The Scotts fungicide you used (the one in the orange bag right?) is pretty weak, and I wouldn't expect it to prevent a lot of disease. Spot treating areas with Immunox that look like they are infected is a better way to limit disease and it's not very pricey, and works pretty well. In addition you should follow good cultural practices, avoid watering at night, no more synthetic nitrogen till fall, mow only when the grass is dry with a sharp mower blade, and don't let it get too long or else that will trap moisture. There are a few natural products you could try minimize fungal outbreaks like Serenade, and phosphites. Do a google search to learn more. Also you have to accept the fact that you might loose a lot of your new grass. When early fall comes around you will have to assess your lawn and determine your course of action, probably an overseed will be in order. Your grass stopped growing so fast because once the first blades start being cut the grass focuses more energy into tillering, so it will get thicker, but not grow as fast. Also top growth slows as the temps get hotter. Here's a link that shows what happens to a cool season grass as temps go up.
http://postimage.org/image/2yocv7vok/

Thank you for your thoughts. I figured it was a fungal infection, and thats a huge letdown to hear that there isnt really all that much that I can do between now and the fall. Are there any chain stores that carry the fungicides/products you mentioned? I didnt see, or at least dont remember seeing, anything like that at HD. Pretty much the only thing they had was the orange bag Scotts.

I was going to call up Tru-Green, but after doing my research... I can do this, its just going to take more research and planning. I'll head over to the closest Pike's Nursery? I THINK that there is another larger Nursery (not a major chain) nearby too that I'll look into for stuff. I've been going through a number of the threads and the names of the chemicals getting thrown around are completely foreign to me. And definitely not anything that the lawn and garden individual at HD mentioned ever.

Immunox is sold at Home Depot. It comes in a black bottle you attach to the end of your hose. Serenade can be found at garden centers, they list where it is sold on their website. The heavy duty fungicides can be purchased at Lesco, I'm sure there is one nearby. Heritage G is a granular broad spectrum fungicide that is very good. Eagle is another good one they carry. You want to alternate fungicide applications to prevent creating resistance. Again, you should be finished applying high nitrogen fertilizers until the fall.

Schweet! There is a Lesco less than 3 miles from my house! I'm assuming that it would be best to go there first to get the good stuff? and then perhaps follow up with some of the cheaper (and less effective) products such as Immunox and Serenade?

Any thoughts on some good reading? I've seen the Scotts book at HD, and see it has good reviews followed by the Lawn Bible.

I can't tell you what you can or can't do, but I would probably do the contrary, stick with the safer less powerful things first. Save the hard hitting fungicides for the very hot and humid days of summer when all else fails. Then again Atlanta can be brutal on a cool season grass, especially young grass, I have dealt with brown patch and pythium where I live up in CT, certainly a much cooler climate. Since you established it in spring, one could make the case that a prophylactic fungicide will keep the grass alive and give it time to mature till the heat breaks, but this means monthly applications of alternating types, for at least 4 months. If you have pets or kids it's probably not the best idea if they play in the yard. Plus there is no guarantee this won't happen every year.

Use tuna cans to measure irrigation. Put several out around the yard. Turn the water on at 8am and time how long it takes to fill the cans. Every sprinkler system is different. Mine applies only 1/8 inch per hour so it takes 8 hours to get an inch. Others put it on so fast it runs off before it can soak in.

The lawn actually looks pretty good for being "new".

I think your desire for quick improvement is probably tripping you up here. Lots of young growth plus too much water is a recipe for fungal problems. The best thing you can do to correct that is to change the cultural habits that lead to the problem.

So, if your grass was growing like crazy, I bet you fertilized before the first flush of spring growth. If so, that is part of the problem. It wears off soon, but you opened the door to fungal problems.

Also, you realized you need to cut back on the watering. Once per week is preferable and dchall gives an easy way for you to convert hours to inches.

Finally, if you spot a fungal infection, start bagging the clippings until you get it under control. That will slow the spread of spores and help contain the problem.

As for fungicides, best of luck. Most are only marginally effective.

Great suggestions everyone! Thank you so much and keep em coming! I am definitely going to pick up some literature on better lawn maintenance.

I'll see if I can round up some Tuna cans (sounds like I know what I'll be having for lunch all week) to test out my irrigation. Thats a great suggestion.

I also would agree that I probably set unrealistic expectations for the lawn, especially considering that I started in the spring. I'm realizing that now after doing some research... its not as simple as mow, water, fertilize.

I'll head to HD get the Immunox to at least apply something to the lawn in hopes of doing something. I do have two dogs and two cats (well... havent seen one in 2 days so maybe I have one now...), so I have to be somewhat careful. Thankfully, the back yard looks muuuuuuch better in terms of health, so I can keep them back there and not treat that yard with anything harsh.

If I do want to attack and address the fungal issues on my lawn so that this issue isnt present or as prevalent next year, and if the fall is the best time to address the lawn overall... How would you guys approach your fall regimen were this your yard?

"to at least apply something to the lawn in hopes of doing something. "

That kind of attitude gets lots of people in trouble.

Most lawn chemicals are pretty nasty stuff. You want to minimize their use as much as possible. For instance, the fungicide you are putting out is designed to kill all fungus. However, the vast majority of fungi in your soil is benefitial, so you kill a lot of good with the bad. Sometimes that is necessary, but you don't want to make a habit of it. When you do have to go that route, you can help rebuild the soil after you get the problem under control by sprinkling some compost around.

Well... I know I shouldnt just start throwing chemicals at the lawn. I figured that something like Immunox could be used to minimize the effect of the fungal infection I'm seeing. Perhaps my use of the Scotts fungicide is partly to blame for the downfall of the lawn? It certainly went downhill just after application.

I guess I'm in no mans land now. I dont necessarily want to use the fungicides if they arent really going to help and have the potential to hurt, but I feel like I need to do something or it will only get worse. I certainly dont have problem feeding the lawn with a compost later in the year if that will bring it back. I think the soil along the front of the yard, along the street, is iffy at best anyways. This area is browning (as seen in the photo above), but last year when we moved in that soil was nearly bare. I threw some seed down at the time and then again in march, but that soil looked pretty pale and clay-like (surprise surprise in GA right).

Slow down and let some of this sink in. Patience is your friend at this point.

If you want to apply compost (not a fertilizer), then do it sooner rather than later. You have already sprayed the fungicides. Compost will restore the beneficial fungi you may have killed off. NOW.

Rather than mow, water, and feed; I would change that to WATER, MOW and feed. Getting the watering right is the most important part. Mowing is easy. Fertilizer is important and also important to get right in the timing. If you are going to use synthetic fertilizer, then timing is important. If you are going to use organic fertilizer, then you can do that at any time. If you feel like you should be doing something, anything, then apply organic fertilizer. Go to the Organic Gardening forum and find the FAQs. Near the bottom of the list is one for Organic Lawn Care. It will give you ideas for how and where to get your supplies without taking out a loan. Compost is the only expensive thing you'll use, but if you are doing things right, you should not need it.