Pelvic Fins for Mermaids

I'm a massive noob and have no idea how to use blender so I'm probably doing this wrong, but I tried making some pelvic fins and I'm having trouble figuring out how to attach the extra fins to the tail? When I add the mesh to S4S the tail itself gets all crusty despite the fact I hadn't touched the tail and only duped the very end part. Any advice appreciated! I'm also planning on trying to make dorsal fins but again that will probably not go well.
If anyone also wants to take over what I started here then by all means go for it! I just wan't snazzier lookin' fins man.


drive.google.com/open?id=1gJhKbR263aJDYdzaWzcGnehddYvXxWQK