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PYRAMID REEFVISION AND PURPOSEWe are a group of experienced divers and ecologists whose objective was the construction of an underwater reef of natural forms that would offer the greatest surface possible where the sea organisms could settle. The construction should also have a great number of close-end holes as it is known that each hole is usualy occupied by only one organism.We come from a country with a very short stretch of shore (47 km) that has been almost totally devastated by excessive fishing, use of trawl-nets and pollution. Four years have passed from the first idea to the implementation as we had to study different types of materials and techniques but , above all, we wanted to create something innovative.Most artificial reefs are namely made of objects that really do not belong to the sea bottom but are only economically convenient.
Under the slogan ATTRACTIVE TO THE FISH we can even find old tyres and drilling rigs.
According to this logic also a disused atomic plant would be "Attractive to the fish".
USEThe PYRAMID is an artificial reef. It is an extension to the CUBE reef and is intended for artificial repopulating and protection of sea organisms that need such type of habitat for their existence. It also protects the shore from erosion and waves and serves for the creation of a real sea forest. The gravity centre of the PYRAMID is in the middle of the bottom which makes it very stable. Its stability is enhanced if we place it perpendicularly to the sea currents and waves.
Each PYRAMID is a unique sculpture of irregular forms. This is made on purpose as regular forms do not belong to the sea. We obtain irregular forms by hammering off some pieces. The PYRAMID is full of holes of different diameters, of irregular forms and eventually with separate entrances. They can be populated by different species that could otherwise not cohabit (lobster, octopus) .
The holes are dark as many animals hide during the day and come out only during the night.
We obtain irregular forms by removing the mould before the concrete has solidified completely and by washing the surface with jets of water under pressure. The result of this procedure is: - irregular geometric form
- rough surface with exposed pebbles
The surface of the PYRAMID is thus increased tree times. CONSTRUCTIONThe construction of the PYRAMID is a demanding job but with some enthusiasm it can be realised.
You need a concrete mixer, a special mould made from thick sheet metal, balloons and experienced divers. The PYRAMID can be dragged into the sea when the balloons are still inflated. This makes it easier to position it near the place where you intend to sink it. Then the balloons have to be deflated, first those in the lower part then those in the upper part. Thus you will prevent the PYRAMID from turning over and you will be able to position it correctly. The balloons are made of plastic that can support the pressure of 350 kg from one side. As the pressure of the concrete is uniform they can support even a much higher pressure. Presently we use three types of balloons:
- diameter 45 cm
- diameter 55 cm
- diameter 65 cmWe are also tying to make a balloon-tube, 120 cm long with diameter of 45 cm ,that will surely make happy such underworld inhabitants that need longer holes.
The PYRAMID is made of sand and cement (Portland).
We use stone chipping made of rocks that are typical for the place where the PYRAMID will be placed. We use Portland cement without any additives. Additives are not necessary as cement is a natural substance with pH neutral. The rocks of our planet are all pH neutral and are thus a natural material to be used in the sea water.
The concrete should be quite dense and not excessively fluid or else the balloons will tend to pop out.
The mould has only one opening on the upper side. You do not need more openings . Why?. Because each balloon has a valve that, when the balloon is positioned, is pressed against the inner wall of the mould by the pressure of the concrete. The balloons are deflated when the mould is removed.
If you want to create a PYRAMID with smaller holes with smaller openings than place the balloons at a distance from the inner wall of the mould. In such case you have to mark the position of valves on the outer side of the mould in order to recognise the spots where the balloon valves are positioned. When the mould is removed open the holes with a hammer and extract the balloons.
You can place any number of balloons of different sizes as to get many different holes of different diameters.
In order to create a rough and irregular surface remove the mould before the concrete has solidified completely. Wash off the not yet solidified concrete with a jet of water by using a high-pressure pump. DO NOT USE ANY ADDITIVES AS THEY ARE HIGHLY TOXIC.To prevent the concrete adhering to the surface of the mould and balloons coat these surfaces with sugar/water solution or cod-liver-oil.
It is not necessary to reduce the pH of the concrete and rock surface as it soon becomes identical to that of the sea water. The pH of the sea water varies at different latitudes (tropic seas have pH 6,5-6,8., northern seas have pH 8,4) and it would be impossible to obtain the correct pH value.The PYRAMID can contain, for example:
- 4 balloons diameter 65 cm = 1.327.32 cm2 = 5.309.28
- 4 balloons diameter 55 cm = 950,33 cm2 = 3.801,32
- 2 balloons diameter 45 cm = 636,17 cm2 = 1.272,34
10.382,94 + 5.907,00
This proves that on a surface of 1,5 m x 1,5 m you can create a surface of 16,3 m2 ( the calculation does not include the diameter of the openings of the holes, as their size can vary, neither the bottom side of the PYRAMID.
You can see the construction procedure in our gallery.If you need advice, help, mould or any element for the construction of such a reef, please contact us and we shall be glad to offer you our assistance.