3g or less = pico
3g-29g = nano
29g-90g = mini
90g-180g = large
180g+ = huge or massive or something, cant really thing of a good word for this one. maybe extra large?
Looks good...although I recall nano on RC goes up to 34 gallons. So to be consistent...
3g or less = pico
3g-34g = nano
34g-90g= mini
90g-180g = large
180g+ = very large (mega?)