Framed tank or rimless?
Food for thought to reassure for a DIY wood frame: Your tank fully filled will be about 1800 lbs (water, salt, rock, sand, glass). That sounds like a lot, and it is a lot for, say, a person to lift.
But it’s not all that much for wood posts. Assuming framed you’ll see about 450 lbs at each corner. This is a trivial weight for a 2x4 to carry. A single 2x4 stud tall enough for a stand is good for about 4000 lbs (including safety factors). You’ll have two or three at the corner depending on design, and then sheathing/plywood wrap will boost it further.
The legs will be working at about ~3 to 5% capacity.
Biggest concern for loads really is ensuring the tank is evenly supported where it wants to be and making sure you have plywood or some sort of bracing on the sides to provide it with some lateral stability.