Im no expert, but it seems to be around 3ft high. But i would go with what you can easily get your hand to bottom of tank and do any work.
Also consider where you will be to view the wonderful creatures.
But most sideboards, cabinets etc seem to be around 2.5-3 ft.
I've heard that fish generally feel safer if they are higher sice most fish predators attack from the top of the water;Don't really know if it's true but generally around 3' high stand is normal