liveaquaria writes their information leaning more towards the beginner. You could keep SPS alive in a cup of saltwater if you could provide the right light and keep the water clean. With nano tanks the water volume is so low that its easy to throw to parameters all of and in most cases SPS is a lot more delicate when it comes to drastic changes like a temperature spike, or an overdose of Ca or Alk. As long as you can keep all your parameters stable, you should have no problem growing SPS in a small tank.