I never heard the term nanoaquarium before reading this book; it applies to very small fish tanks, between three and nine gallons. They can only support certain small plants and one or two diminutive species such as dwarf cory cats, little colorful shrimp or a single betta fish with a snail. The idea is to create a miniature, functioning environment with small aquatic plants and fish in harmony. Compared to the other Barron's books, this one gets quite technical with the water parameters and maintenance details. This makes sense as in the smaller, closely contained ecosystem things can go wrong quickly if not carefully monitored and corrected (so the book informs me). The attractiveness of a nanoaquarium is that you can keep one almost anywhere, due to their small size. The downside is that not as many species can go in there, and you have to more particular with the care. I don't quite think this is the option I want, although they do look very attractive. This book is a good introduction.