The invention of the golden ratio dates back to the classical era, created by the ancient architect Vitruvius, who states:

"For a space divided into equal parts to be agreeable and aesthetic, between the smallest and largest parts there must be the same relationship as between this larger part and the whole space."

Since the Rennaisance period, painters have used and applied the formula to other subjects as well. The golden ratio has even been applied to human faces!

The ratio can be summarized as the small is to the large as the large is to the whole. Mathematically, the whole is 1, the large is 0.618, and the small is 0.382. When drawn on an aquarium, there should be four intersections which refer to the four possible focal points. These intersections can also denote other key areas of negative or positive space which are not necessarily the focal point of the tank. Also, the horizontal lines can be used in creating a horizon line (the line dividing the water column from the plants or substrate). All these statements will be clarified below with the visuals.

In this concave layout with Rotala sp 'Green' and Glossostigma elatinoides, where is the focal point? The focal point lies on the top left hand intersection on the branch where the two mounds of Rotala meet. More typically, a concave layout will have the golden intersection fall on the negative space (i.e. background) between the two mounds.

In this layout, the upper right hand intersection seems to be the focal point ---and also the vanishing point, where the plants end and the negative space (black background) begins. The top horizontal line also fits perfectly with this aquarium's horizon line.

For my third example, I chose a Dutch aquarium. The focal point seems to fall on the colorful Ammania gracilis on the top, right hand side. Is this the correct focal point?

Keep in mind, that these rules are not hardset and that there are several other guidelines you can follow in creating your aquascape. The golden ratio is just one tool out of many.

How to apply the golden ratio to your tank:

When first setting up your aquarium, I find it useful to take out a ruler or measuring tape and mark the aquarium with a marker. Measure the length of the aquarium and multiply that length by 0.618. For example, a 36 inch long tank x 0.618 = 22.25 inches. Draw a vertical line. Now, measure 22.25 inches from the opposite side. Draw another vertical line. Measure the height of your tank from bottom to top and multiply that by 0.618. Draw a horizontal line. Measure the height from top to bottom this time and repeat. When all is said and done, you should have a square in the dead center of your tank with four intersection points just like the aquariums pictured above. If you want to use the golden ratio, now you know where exactly is the focal point, where the horizon line should be located, etc.

Discussion #1:

What draws the eye the most in the three photos? What do you think is the focal point?

Discussion #2:

Using a photo of your aquarium, apply the golden ratio lines. What do you find? Does your aquascape use the golden ratio? Post here to discuss!

Carlos

(thank you Jay for editing and drawing the lines on the pictures for me!)