It looks sinistral (shell grows counter clockwise when viewed facing the apex) like a Physid (aka bladder snail family), can you take a picture with the opening facing the camera? It won't help me ID it much since I only know some of the wild snails in my area not the melting pot associated with the planted tank trade but it's an important character to start with if anyone else might know. A photo showing the tentacles is probably also a good idea.
OK, pretty sure I got this: Skimmed pdf of Burch, J.B. 1982. North American Freshwater Snails and got lucky; page 261 Planorbella scalaris or P. duryi. Both endemic to Florida. These are ramshorns that sometimes (P. duryi) or always (P. scalaris) have a "physoid" (i.e. like a Physa aka bladdersnail) shell shape.
EDIT: I hope this universe counts this ID karma and passes it on to my moss ID thread.