Round fish tank, the five elements belong to gold, can produce prosperous water, so it is auspicious.
Rectangular fish tank, five elements of wood, although leaking, but the two are related, can also be used.
Square fish tank, the five elements belong to soil, the soil can hold water, and it has the power of restraint. Therefore, it is not appropriate to choose a square fish tank with five elements of soil.
Hexagonal fish tank, with six as the water number, so the five elements belong to water and can be used.
Triangular, octagonal or even polygonal fish tanks, the five elements belong to fire, and the fire and water are complicated, which is not suitable for the layout of wealth.