I would recommend double, at 40G min. A 70G is even a better beginner choice. The thing that limits beginners is the start up cost of a salt system. The more salt water gallons you have the more cushion of error you have. Salt mistakes are not forgiving!! They are disasters in most cases. The best advice for salt is to get as much live rock as you can!!!!!!!!!!!!!!! with a lot of current makers. Even if you go nano to start go SLOW and take tiny baby steps. Load it full of live rock and watch it grow for a couple months. Then stuff like a cleaning crew and a couple clowns or a fire fish if you like those. Take a look at my signature and research the algae scrubber info on here, you will learn a lot. Salt tanks are a lot of fun if you take your time and do it the slow way. Just my ten cents thrown at it. As always do your own research and choose the way that works for you. Dont do things because they are kewl, do them because they are right and beneficial to your tank.
