Catching a Grand Slam in southwest Florida (tarpon, snook, redfish and spotted seatrout) on fly is a rare accomplishment. However, it can be done. In fact, we did it a couple of times last year.
All it takes is desire, the ability to get up a few hours before the sun and a little luck.
For tarpon and snook, we concentrate on fish around dock lights. If your luck is good, you'll only need a red and trout after the sun rises. Sometimes you can get all four around the lights.
I use a fly I call a Gibby's Snook Shrimp around lights. It imitates the tiny shrimp and minnows that are attracted to the lights. I've found size of the fly must match the available forage. If it doesn't, you might get skunked.
For this, I used an 8-weight rod, floating line and 9-foot fluorocarbon leader with 20-pound fluoro tippet.
After the sun rises, I'll paddle out into Sarasota Bay and comb the flats for reds. I find your best chance is at first light. Redfish on fly in my neck of the woods is more difficult than catching a bonefish in the Florida Keys. I like to use a baitfish imitation or Clouser Deep Minnow behind a Pop-N-Fly rig.
Trout are pretty easy. I catch most of them on Clouser Deep Minnows or baitfish imitations.