Takahito Mizuno
Nine years have passed since the creation of the “Natural Aquascape” in the Sumida Aquarium, which was considered as the world’s largest Nature Aquarium at the time. We will share a series of behind-the-scenes stories about its creation and maintenance, which has not been talked about much until now.

The Sumida Aquarium’s special exhibition―the Breathing of Natural Aquascape

The oxygen bubbles produced during photosynthesis of aquatic plants, drifting around in the tank and disappearing on the surface of the water, are so soothing that I sometimes find myself gazing at them for a long time. The oxygen formed during the process of photosynthesis not only fascinates us in the form of bubbles, but it is distributed through the water flow, as saturated oxygen in the tank, to the micro-organisms in the filter and the substrate that help creating crystal clear water. In order to make more people aware of the ecological mechanisms represented by the Natural Aquascape, the Sumida Aquarium is holding a special exhibition from December 9, focusing on the cycle of oxygen and carbon dioxide. To make it familiar to visitors, a series of Nature Aquarium style layouts, including 120cm aquarium tanks and paludariums will be on display, as well as workshops and other events. Now at the time of writing this article, we are in the process of replacing the undergrowth in the 7-metre tank and cutting and replanting stem plants before the exhibition and the New Year holidays.

Cutting and replanting of stem plants.
The substrate was replaced when replanting Glossostigma.
After replacing Aqua Soil and adding substrate nutrients, aquatic plants in the Natural Aquascape will again reach the peak of their growth during this special event. Through the beauty of the aquatic plants actively performing photosynthesis and the transparency of the water, we want you to feel the breath of the Natural Aquascape.

*Please check the official website of the Sumida Aquarium for the event schedule and operating hours.
Sumida Aquarium in Tokyo Skytree Town - Official site (