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.

Underwater grassland

Glossostigma elatinoides has become the most popular carpet plant in the planted aquarium hobby since Takashi Amano used it in his Iwagumi layout 30 years ago, and plays a leading role in the 7-meter aquarium here at the Sumida Aquarium. This species is a perfect undergrowth for the aquascape, depicting spectacular grassland and mountain landscape. Through working on this aquascape, we have inevitably enhanced our maintenance knowledge and skills because nobody had planted it in water over one meter deep before. First of all, in order to maintain this sun-loving aquatic plant over a long time frame, it is essential to apply fertilizer according to its growth stage. Because the planting area is considerably large, the plant’s growth speed varies from place to place. Besides daily application of liquid fertilizers, the amount of Bottom Plus given is modified at the areas where growth is slow. On the other hand, the fast-growing areas need to be trimmed to match the surrounding area. The point to note here is that if you cut deeply into thick overlapping Glossostigma, it will not only look unpleasant, but it will also take a long time for new shoots to grow back. Therefore, in order to keep the layout in a good condition on a daily basis, it is important to help them grow uniformly with frequent trimming. We also needed to develop specialized tools because it would be extremely difficult to perform such a delicate task from the top of the tank. After several improvements and further tuning, the tools enable us to perform trimming tasks with the same level of accuracy as in a much smaller, ordinary-sized tank. As the result, this beautiful Glossostigma grassland has been accomplished as we see it today.