The plant in question grows very nicely on my window sill. It is a terrestrial plant, that's for sure, and don't let the petstore tell you any different. Many petstores commonly sell submerged plants. They are not true aquatics.
I'm truely sad quoting my own post, but I did some digging and the varigated plant you have is Dracaena sanderiana, which is definitely not an aquatic. It's a common house plant, hence it doing well on my window sill outside of my aquarium. Just for your information. It bugged me not giving you a scientific name in my first post.