Just as important as what convict2161 mentioned ... IMHO
.... Is the type of stand. Weight on floors become an issue when you get around a 50gal or larger. The way I figure, if a second floor and support a couch / sofa with 2 adults, it should hold 45gal and down.
With larger tanks... How the weight is distributed becomes an issue. For those tanks, I don't like metal stands that have 4 legs at the corners. That just pinpoints the weight in a small area. Stands that resemble cabinets with a wide base touching the floor better distributes the weight.
75g Planted Barbs Denison, BlackRuby, Tiger, Albino Tiger, Green Tiger, Cherry, Gold, Checkered, Odessa.
NonBarbs Cardinal, Neon, RummyNose, Bloodfin Tetras, Z. Danios. 1RTS. Amano, Bamboo, Ghost & RCS. 20g Long Shrimp Tank RCS, Tiger, Amano.