Did some more research it looks like Yellow Nutsedge. Now to figure out how to get rid of it.

if it is in fact nutsedge you can use a product called Sedgehammer.

Before you use chemicals, yellow nutsedge usually only grows in swampy soil. How often do you water and for how long?

Every now and then I get a few strands of nutsedge but then it stops raining and it goes away. When the city came to fix my unbroken water meter, they replaced the soil with junk full of bermuda and nut sedge. It all went away naturally under my watering program.

Where do you live in FL? Would you characterize your soil as sandy, pure sand, or something else? If you toss a half cup into a jar of water does it all sink immediately to the bottom of the jar and leave clear water on top? Or does something else happen? Cloudy water? Different layers of sediment?

Dchall, she is in Florida and now is the rainy season. Its not uncommon to get 1-2 inches a rain a day. The soil is sand so it drains away very fast.

Yesterday I had 2 inches at my house in 1 1/2 hours. Not a single puddle formed during this storm.

Thanks for the responses everyone.

I live in tampa FL we are allowed to water 3 times a week Sun, Wed, Fri. On those days i waster twice a day for 20 minutes. Is that too much?

i don't know the size of your lawn but 20 minutes seems way too short and twice a day is too much during the day. Try watering deep and infrequent so your roots of the grass get used to digging deep to find some water. But most importantly use your eyes. Your grass will tell you when it's thirsty. It will start to turn a grayish color and then you know it needs some water.
Good luck!

Botanbill, while I appreciate, sincerely, your input, if you live on sugar sand dunes and he/she doesn't, things could be different. It sounds like you and the OP might be relative neighbors, but I've been here a loooong time. FL is one of those places where you can't assume anything about the soil in different parts of the state. Tampa is one of those places where if you guess, you're probably wrong. While I expect sand, there are a bazillion lakes and ponds around there. Those don't form on pure sand, so there's a strong possibility he/she has something else.

jmandawg, Do you get puddles when it rains? Do you still water even if you get rain?

That does seem like an excessive watering frequency. If you can get your grass roots retrained to grow deeper in the soil, I strongly suspect you can restrict your watering to once a week or even less often. But if you're on sugar sand, then botanicalbill is going to have more to say about it.

When I backfilled my back yard I used what amounts to sugar sand. It's 8 inches deep at the deepest, which I realize your soil is probably 80 feet deep, but still - it's sand for the entire grass root zone. That sand grows the best grass I have. After 12 years of organics the sand is black when you look at it, but when you put it in a jar of water, all the white sand sinks immediately to the bottom and all the black organic stuff floats to the top. That grass gets watered once every other week unless it rains. So far this year it's only been watered by me twice. We got some heavy rains and it really hasn't needed more.

jmandawg again, generally the world gets by watering deeply and infrequently. Generally that means watering one inch of water, all at one time, and doing it once a week when temps are in the 90s. Other factors to consider are soil type, soil depth, grass type, grass height (yours should be mowed at the mower's highest setting), shade, clouds, wind, humidity, organic content of the soil, and some others. After taking all this into consideration, there are only a few places where the general advice would differ. One of those places is the area from Green River, Utah south to the Mexican border and west to Indio, CA and east to Junction, TX. That area is different because the soil is often gravelly. The sand is coarse and really does not hold any water. If Florida is another location where the general guidance does not apply, I have not heard about it. But I am certainly willing to listen to actual experience of people who have tried to grow deep roots and still required frequent watering.

I'm still interested in the soil conditions for jmandawg.

I do live on a canal,but there is a sea wall. I've dug down a couple feet and it seems like there is a top layer of dirt, and then dryer sandy dirt underneath that.

I just set my sprinklers for 3 times a week (Sun, Wed, Fri), (once per day as opposed to twice per day) at 1am, for 20 minutes per area. Hopefully that will be enough water for the grass.

Do you think it should be 30 minutes per area? I guess i need some sledgehammer to get rid of this nutsedge.

Before you get the Sedgehammer, try backing off on the water a little harder. Instead of 3 days per week, try watering 30 minutes twice a week. Watch it very carefully. If you see any part of it drying out, then water immediately but water a little longer that time. If you could eventually back off to watering once every 2 weeks, that nutgrass would die out. Your temps are barely in the 90s, but your humidity is oppressive. Between the relatively cool heat and high humidity, your grass should go a lot longer without a drink.

Next time you water put out some straight sided cans and measure how much water you get in 20 minutes. That amount is very important to getting your water under control. All the grass should need is one inch, ALL AT ONE TIME, every week or two.

Thanks for the advice dchall i'll going to give it a shot and see how it goes! I'll switch over to Sun/Wed for 30 minutes. I will report back in a week or 2.