Hello, first time homeowner here, been in the home for 2months now. Definitely a DIY type, or i wouldn't be here :)

The front yard is a different grass than the backyard which is annoying in it's own right... Front I'm 99% sure is bahia, and as you make your way to the back it transitions to something else. I need to concentrate on the front first.

From what I can tell it looks like bahia grass, the seed stalks are identical to http://www.pasturegrass-seed.com/images/stories/bahiagrass_seed_stalk.jpg and the grass looks like it from all the research I have done. Before moving in I fertilized and the current lawn went from dying to a bright green. We have irrigation and I have raised the sprinklers which were way too low underground. The previous owner didn't use the irrigation system apparently.

Not a fan of bahia so far, and in its present state it is kind of sparse, the established growth is very green and healthy, but each 'growth' seems spaced out and you can see the soil in between, to restore it definately needs to be seeded. Lucky to have next to no weed growth though.

I can't afford to re sod this year, with all the expenses of the new home yet, wondering for recommendations.
Are there other grasses I can plug the lawn with that will overtake the bahia in time? Or is the only option to completely remove the current lawn?
Thanks for the advice!