The aquarium stand

In[7]:=
  o = 0.25; (* overhang *)
  d = 0.1;  (* thickness of stand *)
  h1 = 3;   (* height of stand *)
  stand =
    Graphics3D[
      {Cuboid[{-o,-o,-d},{w+o,l+o,0}],
       Cuboid[{0,  0,  -h1},{d,d,-d}],
       Cuboid[{0,  l-d,-h1},{d,l,-d}],
       Cuboid[{w-d,0,  -h1},{w,d,-d}],
       Cuboid[{w-d,l-d,-h1},{w,l,-d}]}
    ];

In[8]:=

  Show[stand,aquarium];

Up to Aquarium