I'm going to go against the flow a little (pun intended : ) ). While I agree that a buried anode is preferred, adding one to the water flow isn't a terrible idea. Given that you have a polymer walled vinyl pool, it isn't as effective for you as it would be for someone with more metal in their pool construction.
It adds a little zinc to your pool, but in New Jersey you'll replace enough water every year that it shouldn't be a problem.
Having said that, If you can return that anode and get a buried anode and connect it to your bonding grid as Casey did, that would be best.