Mermaid doesn't have specific showtimes. Its constantly cycling so you just get in line and usually see the next show or the one after it. it really is a cool show if you like Ariel but its short.
Its good you added Pooh! its soooo much better than the Dland version. Also a lot of times when you get a Pooh FP they give you a free bonus Philharmagic Fastpass (which actually isnt that valuable unless the line is really long since u can usually see the next show in the standby line).