Steel stand questions.

[Fishess]

Hello, i'm completely new to building stands, and i don't know much.. I kinda need some help finding right steel size, and thickness.
My aquarium is about 50 gallon.(190L) size 33"x15"x20" (83x38x50Cm) Stand will be about same size BUT 40" (100Cm) high
Was thinking making stand from square steel tubing.. But i don't know much about steel structural strength.
Should i build from 2"x2" 1/8" thick? or Will 1.5"x1.5" 1/8" do the job?
I want the stand to be very, very strong, and safe..
( I will be adding thick wood on top of stand. And 3x wood shelves in middle on chains, that will be attached inside of top frame 4 corners.)
Thanks for any tips in advance.
Design shown in images:

 

[N1Husker]

Looking at your configuration, 1.5 square tubing will be more than enough. Manufacturers build much flimsier stands than yours will be, just using angle iron.