Systems - The Structure

Building A Public Marine Aquarium III

Written by Andreas Iliopoulos Tuesday, 04 June 2002 01:00

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In this part I will discuss the following:

• equipment, setups and communities and 
• display tanks, quarantine tanks and pond

of the Mediterranean Public Aquarium of Kini Bay (Concept, machinery, rationale)

I became involved with the project "Kini Bay Public Aquarium" at about the same time I received an invitation from the marine biologist Dr. Pascal Divanach (director of the Institute of Marine Biology of Crete - http://www.imbc.gr) to visit the I.M.B.C. to discuss my collaboration with the people of the Institute for the construction of a really big Public Aquarium which is going to be built in Heraklion, Crete.

After that meeting, I went straight to Syros, and after auditions with the financial manager of the Institute (M. Papadakis), and the director of Biological School of the University of Heraclion, Crete (Drs. M. Kentouri), I had the first meeting with the people of the Municipality of Ano Syros. I shall have to say that, along with Dr. Divanach, they shook me up with their questions, but it seems they were not disappointed from my answers, so the opportunity to work on this project was still in existence.

During the first talk I had with the Supervisor Architect of the Technical Services of the Municipality S. Bousias (Architect of the University of Venezia), I was given some schedules to take a look at what they had in mind. I found out that these schedules where not correct. The aquaria, as they were designed, numbered more than thirty, but were very small and totally unsuitable for keeping Mediterranean marine organisms. So we sat down together and redesigned the whole showroom.

The result was fifteen aquaria only. Eight of them measure 2.5 meters of length, 1 meter of width and 1.3 meters of depth, with a capacity of about 3,250 liters. Four of them are 2 meters long, 1 meter wide and 1.3 meters deep, with a volume of 2,600 liters. These twelve aquaria were the easier ones to be made, with only one glass window, in contrast to the other three, in that their shapes are not the familiar parallelepiped tanks. These are set in the corners of the showroom with two or even three glass windows. The dimensions of the first of them is 1 meter long, 1 meter wide and 1.3 meters deep (for the one side of the tank) and 2 meters of length, 1 meter of width and 1.3 meters of depth (for the other side). This tank has a total volume of about 3,900 liters. Another is about 3 meters long, 1 meter wide and 1.3 meters deep at one side and 1.5 meters long, 1 meter wide and 1.3 meters deep at its other side. It measures a volume of about 6,000 liters, and has three glass windows. The biggest tank of all, also with three glass windows, is placed in one corner as well, but its shape is not the Gama - shape as the previous two. It measures a total length of about 5 meters, a width of about 1.4 meters and a depth of 1.3 meters. Its volume is about 9,000 liters. We also designed a pond with a shape of a ∞ (you may say either it is number eight or the symbol of infinity), with a volume of about 12,000 liters.

Unfortunately, the water volume, which I will have to deal with, will be less than previously mentioned, as the water level in the opened concrete tanks will be at a maximum of 1 meter of depth.  I want it this way to prevent the loss of fishes that probably will try to jump out due to stressful conditions. Aquascaping with stones and sand will consume some of the water volume, also.

The glass windows I shall use are 19 mm thick, and they will be held in place with stainless profiles.

Another thing that I had to decide on was the quarantine room. I designed it, equipping it with five plastic tanks, for keeping and observing the specimens before their introduction into the display tanks. I designed the tanks with an internal filter within their structure. Their volume is about 1,000 liters of water each (150cm x 100 cm x 80 cm). I designed their filters exactly the same way I had designed the filter for Dr. George Reklos' non - m'buna tank. They will have the same function with the internal filter that I designed to support his system back in 1998, and their capacity is 17% of the total water volume.

A submersible electromagnetic water pump with a turnover of 5,500 l/h will circulate the water from the tank, to the filter, and then back to the tank (Hailea, HX6550).

I will not install protein skimmers on the quarantine tanks, but I shall support them with very simple, air driven, self - made, surface skimmers. The overflow combs (Aquamedic) I will install on the filters' compartments will help with basic skimming also. RENA AIR 400 double outlet air pumps will support both the surface skimmers and the tanks with air. I shall use RENA air stones, as well. These air stones have the advantage of being able to be unclogged (with a use of fire from a lighter), so they can be used for a long time before the need of replacing them.

The filters I have designed for supporting the tanks are self - made, wet - dry ones, consisting of a plastic box filled with media placed on the top of every tank with an inlet of ¾ inch and an outlet of 1½ inches. The water has to pass, after the inlet, through a trickle plate, so it goes down spraying the media (SAC and bactoballs). The volume of the biological substratum that will be placed in the plastic containers will be the 2% of the water volume of the tanks. For biological substratum, I shall use Bactoballs with an active surface of 300 m²/m³ (Aquamedic). Two filters have been anticipated for the bigger tanks and only one filter for the smaller ones.

Powerful submersible electromagnetic water pumps (RENA 6000S) will feed the filters with water from the tank via trickle plates (Aquamedic), with a flow rate of about 2½ times the aquarium water volume per hour.

The water will pass through Super Activated Carbon (Aquarium Pharmaceuticals), before it reaches the Bactoballs, so chemicals, odors, colors and undesirable organic material will be removed first. The total quantity of SAC I shall use is 500g for every 100 liters of water, and I will add monthly 20g for every 100 liters until I reach the quantity mentioned above. It is going to take a period of 25 months to put in the whole amount. I am going to replace 30% of SAC every five to seven months (the time that SAC remains active), while I will wash the remaining 70% of it with aquarium water. I have ordered about 360 kg of SAC for this purpose. The extremely porous surface of SAC gives me the convenience of having both chemical filtration and additional biological substratum with the same medium. There is no need of buffering substratum, because seawater will enter the system continuously, so pH will remain stable constantly.  Skimmers will also help with that effort.  

The water will flow back into the tank, with the help of gravity, from a drainage hole serving as an outlet on the bottom of the plastic container. The filtering materials will be held 5 cm above the filter containers' bottom with the help of Grate screens (Aquamedic).

Suitable, motor driven, protein skimming devices will also support the tanks. I have chosen the Turboflotor skimmers' series (Turboflotor 5000 Baby), made by Aquamedic. These skimmers are equipped with Venturi system pumps (Eheim 1060 l/h).

Their needle wheels can efficiently mix water with air in such a way that fine air bubbles are in contact with water for an extended period of time. The smaller tanks will be supported with one of them, while the bigger ones will have two.

The submersible electromagnetic water pumps that will feed the skimmers have a flow rate of 3.500 l/h (more than 1½ the water volume per hour) and for this purpose I picked the OR3500 (Aquamedic) power heads.

This way, proteins and organics will be removed before they begin to break down, so I shall have lower Biological Oxygen Demanded (B.O.D.) and Chemical Oxygen Demanded (C.O.D.), as well as a lower nitrate buildup. Removing organic acids will also help maintain the pH.

The tanks will have overflows. Through them 20% of the water volume will be removed and seawater will refill the tanks daily.

This water is going to be passed through a professional chiller, to keep a temperature of 16ºC - 20ºC year round. I chose the SK- 6 Aquamedic model suitable for non-isolated tanks, even if the water container that seawater will be collecting in is isolated. From this container, the water will flow through PVC pipes to the tanks by gravity. The tanks' room is also isolated.

For the pond I am going to use a heavy duty immersed water pump, with a water flow of 17,000 l/h (ATK, MP 170 70) and a really big skimming device (Turboflotor 5000 Twin, Aquamedic) equipped with two water pumps (Eheim 1.060 l/h). The height of this device is 1.97 m. I am going to install a water pump with a water flow of 5,500 l/h, for feeding the skimmer (Hailea, HX6550). The plastic container that I designed to play the role of the filter box requires more than 200 liters of bactoballs to reach capacity.

Both the tanks and the pond will be as oligotrophic as possible. I believe that by seeding both of the tanks with "live rock" and "live sand" and with the help of the high quality artificial lighting, algae will flourish, not only achieving a natural surrounding, but reducing nitrates. I will control the algae with herbivorous species (i.e. Sarpa salpa, Parablennius sanguinolentus).

As you may have noticed, I have not used any mechanical filtration except the sponges installed on the water pumps that I have used as pre - filters. The reason for that is that I do not want any heavily polluted medium in the system. All the free particles will either be collected in pre - filters, or they will turn into sediment on the bottom of the water pumps that feed both filters and skimmers. I shall perform siphon cleaning of the area to prevent any sediment accumulation there.

Lighting is a very important thing in display tanks. So I had to do a lot of research before I came to the right conclusion. Marine aquaria, especially, are relatively difficult concerning this topic. Considering, also, the quality and quantity of natural light in my country (known as the "richest" light all over the world), this was even more difficult.

After studying every available measurement and chart of light intensity underwater, lighting parameters, transmission of visible light in water, spectral diagrams from bibliography and commercial lighting devices' prospectuses for marine tanks, I finally chose the AP600WX Deluxe (ARCADIA) light hoods. These stainless light hoods bear three Metal Halide bulbs of 150 Watts each and two Actinic blue fluorescent lambs of 9 Watts each. It takes more than fifteen minutes for 100% of the light that is produced from the device to be emitted. The lights will be switched on and off from a timer. This helps the animals to not become stressed from a sudden light flood (imagine that the aquaria are placed in an underground isolated room).

I had no lighting problems with the pond though, as an atrium will support it with natural light - and we have a lot of it in our country - year round. I had to cooperate with the electrical engineer on the electrical installation of the whole building, as well.

There are many devices using electric power, and many others that will have to work with the help of automations (i.e. electromagnetic bulbs).

The reason I mention the brand names of equipment I will use for this project is that I have already tested this equipment for home aquaria, though not in a project like this. I shall test the same equipment for more high performance systems and we are going to need a lot of data for a reliable evaluation (sort of a test drive).

Anyway, the biggest problem I have with this very system is stock. First, Mediterranean species have not been studied as ornamental aquatic pets, so it is not easy to obtain information about keeping them in captivity nor is it possible to obtain them from distributors of ornamentals. Another problem is one of compatibility.

Only some of the Lessepsian migrants are available in the trade of ornamentals, because marine animals from the Red Sea are not widely imported as aquarium pets. So I will have to begin a whole mission to educate local sea harvesters and scuba divers for this purpose. Fortunately, a Nautical, Cultural and Ecological Association does exist in Kini Bay, so I shall have some help from the scuba divers that are members. I have to design different traps and invent ways to capture the different species of wild animals. The animals will have the advantage of environment, too. I will have to be very careful with the wild caught specimens, to better acclimate them into captivity, since they are going to be juveniles or, at least, semi adults. I am going to have a great responsibility for their well being in the tanks. You can say either that I am very moral or very stupid, but that is the way I feel about it.

Because fifteen tanks are not enough to exhibit the vast diversity of Mediterranean species, I will have to make up my mind - maybe several times - about the species that I shall ultimately keep in these tanks. Similarly, it is difficult to decide on the communities that I want to form in the tanks. I am basing this decision on my observations in the field, underwater photographs and attestations from the local sea harvesters, fishermen and scuba divers.

The fish shops downtown are a good source of information too, as the assorted fishes I see in their crates early every morning give me some idea of the wild underwater communities.

My idea is that: if these species have died together in the same area (during harvesting) then, they used to live together in this area, also, so I can house these species together.

Local names of the species and my knowledge of their scientific names only causes a great mess also, as, for instance, Lophius piscatorius means nothing to harvesters.

The people here have told me about some species that have become either extinct or endangered in the last years from the local underwater environment. So I would like to try to breed Hippocampus hippocampus and H. ramulosus in captivity and I also want to cooperate with the locals in constructing at least one artificial reef made with used car tires so that the fishes' communities may thrive again. My target species are Sciaena umbra, Anthias anthias, Apogon imberbis, Lepadogaster lepadofaster, as well as several Bream, Wrasse and Grouper species.

What we want to do is to encourage the recreation of typical Mediterranean reefs with their natural inhabitants living within their safety. It will be the pleasure of the scuba diver to pay a visit in the Aegean Sea to admire the marine life that has such wide biodiversity in the Mediterranean. The reason is that aside from the species that are living permanently in the Mediterranean Sea, there are many Lessepsian migrants living in these waters (more than two hundred have been recorded after 1967), and a lot of species visit the eastern Mediterranean basin for spawning.  These species stay in the Aegean Sea during spawning seasons until their weaning, or even adulthood, because of the complexes of reefs occurring between the islands that provide shelter to them. The great depths of eastern Mediterranean attract large nomadic predators, crustaceans and marine mammals, and the offshore estuaries are suitable for spawning and growing of fry. It seems like all of the Aegean territory is a sanctuary for Mediterranean marine life. Many species from the Atlantic Ocean enter the Mediterranean also. The Black Sea is in very poor environmental condition, so the preservation of the Aegean Sea is of a great importance for the Europeans and the local population that it is living from the exploitation of the Sea itself.

Quarantine tanks

This is the 3D view and the overview of the five Quarantine tanks. I designed the same internal filters as the one that supports the non m'buna tank of Dr. Reclos. The same principle and the same way of functioning is also applicable for these filters. Water enters the first chamber from the top and the bottom trough overflow combs. That will be the Chemical media chamber as well (Carbon Activated). Because of the very fine quality of the product I shall use, this very carbon will work as a biological substratum as well. Its very porous structure enables it to function like that.

The second chamber will be filled with one hundred liters of biological substratum (Bactoballs) and in the third one the water pump that turns the filtered water in the tank will be housed. You should have noticed the absence of mechanical media. Any particles in the water will sediment in the first and in the third chamber. They will be removed by siphoning those chambers frequently.

 

 

 

Our good friend Takis Tsamis had the kindness to lay out the plastic self made filters I designed to support the tanks of the Mediterranean Public Aquarium. The Trickle plate, with a great number of holes drilled on it, which force water to sprinkle the media in the nature of rain, is installed on the top of the plastic container. About thirty six liters of Bactoballs will fill the container. Five centimeters from the bottom there are four pieces of Grate plates, so water returns to the tank from the outlet without keeping the bactoballs submersed. On the top cover of the container there are two holes drilled. One with a diameter of ¾", will serve as the water inlet and one measures a diameter of 12 millimeters. Through the second hole air will be sucked in the filter, so Nitrifying bacteria will be supported, as they need oxygen to operate. Finally the outlet is double the lumen of the inlet (meaning 1½"), to prevent flooding in the container. On diagramm 3 the bactoballs are visible.

Self made Wet - Dry filter

Below you can see the plastic self made filters I designed to support the tanks of the Mediterranean Public Aquarium. The Trickle plate, with a great number of holes drilled on it, which force water to sprinkle the media in the nature of rain, is installed on the top of the plastic container. About thirty six liters of Bactoballs will fill the container. Five centimeters from the bottom there are four pieces of Grate plates, so water returns to the tank from the outlet without keeping the bactoballs submersed. On the top cover of the container there are two holes drilled. One with a diameter of ¾", will serve as the water inlet and one measures a diameter of 12 millimeters. Through the second hole air will be sucked in the filter, so Nitrifying bacteria will be supported, as they need oxygen to operate. Finally the outlet is double the lumen of the inlet (meaning 1½"), to prevent flooding in the container. On diagram 3 the bactoballs are visible.

This is a 3D ground plan of the underground hall of the Museum of Traditional Fishing Vessels, Fishing equipment, Marine organisms and Sea Shells that it is built in Kini Bay, at Syros island. The project was constructed from Ano Syros Municipality.

In this underground hall the visitor may see fifteen (15) marine tanks, that will house Mediterranean species, set on the right side of a rocky corridor (3). A Screening Hall (5) is constructed as well, near the main Exhibition showroom (6). On the one side of the exhibition showroom a Pond (7) is set under the atrium. Behind the tanks there exist Operative corridors (4) that are running all over the underground hall. Through a door (8) the personnel will be able to move from the operative corridors to the Quarantine room (9), while doors (12) isolate the corridors from the Show room with the tanks. At the lowest side of this hall there is a room (13) that the main Pumps and manholes for the tanks' drainage are built.

 

 

Acknowledgements

Many thanks to Takis Tsamis for the graphic designs in this article.

 

 

 

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