Picture of a couple standing in front of a floor to ceiling aquarium built by Reefscape Australia Aquariums in Africa.

Reefscape Australia Aquariums go to Africa to build a big aquarium tank in Zanzibar


Location: Africa
Role in Project: Concept Design, Structural Design, Acrylic Supply, Build Supervision
Year of Build: 2011
Size: 25,000 liters +
Construction: Concrete, Steel and Acrylic
Time in Construction: 6 months
Annual Visitation: N/A



Reefscape Australia Aquariums was approached by Kempinski Resorts and Hotels by email. The initial email read; "Can you deliver a 6m x 2m x 2.4m high acrylic aquarium tank to Zanzibar and put fish in it?"

Reefscape replied, "Sure.... but we respectfully suggest a feasibility study might be an idea, before we do."


The requirements of the hotel were that the aquarium was to be 6m long, 2m wide and 2.4m in height and that it was to display colourful tropical marine fish.


Much investigation and debate within the Reefscape Australia team ensued. Would it be easier and more cost effective for the client to build a concrete aquarium and install acrylic viewing panels, or for Reefscape AustraliaAquariums to build an all acrylic aquarium tank and deliver it to Zanzibar? Was a reliable maintenance team available in the area? How would water changes be carried out? How would the aquarium tank even get to the site?


Bear in mind, in remote areas of Africa there are no roads, construction materials we take for granted are not available and workmanship can be less than optimal.


To add to the challenge, sea water tested in front of the hotel showed elevated levels of phosphate. Phosphate makes an aquarium tank quickly become full of unsightly algae. Fresh water tests also revealed high levels of metals. Metals found in water used to top up an aquarium as fresh water evaporates, can quickly concentrate and poison invertebrates and coral. These "site constraints" normally call for source water, either fresh or salt, to be pre-treated prior to use in the aquarium system.


Running costs of an aquarium of this scale must be carefully evaluated and discussed with clients prior to concept design and long before a life support system is proposed. When an aquarium tank is 25,000 litres in volume, synthetic salt mix costs or toxin removing resin costs can quickly shelve even the most modest of aquarium projects long before structural design even begins. Big tanks are expensive to run unless they are designed carefully.


On further project scoping, a reliable building and rigging team were found in the area and a project viability study could be carried out. Reefscape Australia Aquariums concluded from their study that the most efficient solution for the client would be to build a large concrete tank with 2 large acrylic viewing panels. Reefscape Australia Aquariums designed a nutrient sink tank which removed phospahtes from sea water pumped from the hotel jetty.


Reefscape Australia Aquariums collaborated with local officials to understand local marine legislation, building codes and locally available building materials.


Reefscape Australia Aquariums then structurally design an appropriate aquarium tank and life support system that would meet the client's requirements in both appearance and budgeted running costs.


Reefscape Australia Aquariums worked closely with the appointed builder througthout the build process and nutrient sink start up.


Water samples taken from the nutrient sink recorded decreasing levels of both phosphate and nitrate over 6 weeks of testing. Test results recorded negligible levels of both chemicals at the end of this time.



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