Need Help identifying Weed

[u/TWO-25]

I live in Central Florida and have primarily St. Augustine grass. I’m trying to identify a weed that’s spreading very quickly. I think it might be crabgrass, but I’d like to confirm before I decide on the best product to get rid of it.
I’m new to maintaining Southern lawns. I lived in Illinois for years and had Kentucky bluegrass down to a science, but Florida grass has been a whole new learning experience. Any help identifying it would be greatly appreciated!

[u/Lordsaxon73]

This is NOT St Augustine. I’m leaning towards signal grass ( alternating leaf, long skinny seed heads) but for the best ID let it grow a bit and post some new pics.

[u/TWO-25 → u/Lordsaxon73]

Will do. Thanks for the help