Distressing and Challenging Days of ADA Staff Engaged in Maintenance of Massive Nature Aquarium
(It is described Aqua Journal vol. 244 page 36-37)



Mr. Shunpei Sasage
Aqua Design Amano, Aquarium & Plants Maintenance Department


“Struggled with water quality control in the initial stage”


Since it is a massive Nature Aquarium, setting up of aquarium environment, along with the layout creation, was never an easy job. Since a lot of wabi-kusa was used for this Nature Aquarium, the water quality initially looked good with smooth growth of beneficial bacteria and excellent absorption of nutrients. However, this good condition did not last long. It was observed only immediately after the setup. Later, the aquarium faced sudden change in the environment and experienced an algae outbreak due to water pollution caused by decayed emersed leaves and algae-eating animals added to the tank. It took a long time for beneficial bacteria to start working to purify a massive amount of water (160 tons). The initial control of water quality was extremely difficult.


Meanwhile in Portugal having dry and rainy seasons, water is a more precious resource compared to Japan. The country imposes strict regulations on water treatment and the water discharged from aquaria must meet certain requirements. To satisfy such requirements, Oceanário de Lisboa has established the system that the effluent is sent and deposited in a water tank for processing before being discharged outside. Under this system, daily water discharge amount is limited and therefore, the amount of water change is also limited accordingly. In fact, we really had a tough time setting up this Nature Aquarium under such a condition. For daily maintenance of this aquarium, we do most of the works on the bridge crossed over the tank. This bridge was made upon the request of ADA. It is a very strong aluminum bridge which is light in weight and corrosion resistant. We usually sit or lie on this bridge to do the maintenance work.


The “Forests Underwater” is maintained using rich know-how of both ADA and Oceanário de Lisboa. I will work hard on daily maintenance so that this globally renowned Nature Aquarium will impress many people as long as it is exhibited.




Mr. Daichi Araki
Aqua Design Amano, Aquarium & Plants Maintenance Department


“Advice to Control Naturally”


In April last year, I received an advice from Mr. Takashi Amano who attended the opening ceremony of “Forests Underwater”. He said, “Aquatic plants look too tidy overall. I want more daring nature and wildness. But it doesn’t mean that you can just leave everything as it is. This is a difficult part of this aquascape maintenance.” As I tried to figure out what Mr. Amano had said while doing maintenance, I realized that layouts need ‘wildness’ as the tank size gets greater. When we consider this point, the maintenance of stem plants is very difficult. In the daily maintenance, I adjust the pace of trimming and replanting of stem plant cuttings to keep the aquascape close to the image Mr. Amano had in his mind.


Meanwhile, this tank has some locations prone to algal growth. When aquatic plants become lush, algae also grow actively most likely due to stagnant water. To avoid this problem, we trim short the aquatic plants that were planted in a location that can block water flow or we try to decrease the density of these plants. I also learned from this Nature Aquarium that the making of water flow path in the tank is very important for the maintenance of aquascape, because the larger the tank becomes, the more locations with stagnant water it will have. As a maintenance staff, what I feel great about this Nature Aquarium is its massive scale as if it were a real river. I think this feeling of mine can hardly be shared with others unless they see this Nature Aquarium with their eyes. So, I hope as many people as possible come and see this “Forests Underwater”, which is Mr. Amano’s masterpiece.


“Control naturally” – this is a great advice Mr. Amano gave me. Keeping this always in my mind, I will work hard maintaining this great Nature Aquarium every day.





Mr. Yasufumi Shibata
Aqua Design Amano, Aquarium & Plants Maintenance Department


“Experience of Diving in Nature Aquarium”


We have been always doing maintenance of aquaria from outside of the tank. Now, we introduced aquarium diving as a new efficient approach of maintenance to solve the problems that we cannot handle from the outside of the tank.


We at ADA had no experience in diving in Nature Aquarium and I myself never imagined that I would become an aquarium diver. If it is a fish tank, I would not hesitate much to dive in. But this is a planted aquarium and I felt anxious in the beginning because diving might damage or spoil the aquascape. When I dive in the aquarium, I always try to do the maintenance gently, carefully and patiently. After gaining considerable experience, the maintenance by diving has now become an essential method for keeping the aquascape neat and tidy.


On the other hand, the diving is physically very demanding compared to the maintenance work performed outside of the tank. It is deal to do the maintenance underwater for long hours, but about 2 hours are practically possible because the body heat is gradually lost in the water. Since we know the limit, we determine priority of the works to be done before diving so that the maintenance is performed efficiently within the limited time period. I think this is a key point of the dive maintenance. There are things we can see from the maintenance works performed inside and also from the works done outside of the tank; and both of these works have advantages and disadvantages. I believe that by combining the advantages of these two different approaches, we can maintain this “Forests Underwater” in a good condition for a long period of time.


I often face difficulties in overseas environment with different language and culture. Yet, I appreciate the precious opportunities that I cannot experience in my home country, both in my daily life and aquascape maintenance.