Dats can get up to two and a half feet. What Rumblesushi is probably trying to say is that in most cases your dat will not achieve its full size. So maybe he meant nine inches. Your 160g should be fine for quite a while since dats grow very slowly. If your going long term I would look into buying a 400g tank. But as of now your tank should be just fine. Good luck and post some pics.
that's why...i've read this thread several times thinks that there are something wrong and realize that he must meant inches instead of feet ... lol...