You wont need to spend too much time if you are simply researching the animals! Back when I went to Sea World on a school field trip, we had a pretty long worksheet to complete and we did everything in one day with no issue. Take into account it was during off season.
Being a SW fanatic and going almost every weekend growing up, I couldnt imagine not wanting to spend the entire vacation there but from experience I have found that most families find SW a one day event, some returning the next morning to redo anything they heavily enjoyed or squeeze in the show they missed but if you are planning on hanging around each attraction to learn more about the animals, you could spend two days at SW and then visit Aquatica on the third!
Make sure you look for the SW employees with education patches on their shirts! They are pretty knowledgeable about the animals they are dealing with and love interacting with families and young ones!