© Advanced Aquarium Technologies

Face-to-face with Piranhas

Looking is in the past, experiencing is the future: Visitors at aquariums and zoos want to observe animals up close and personal. Transparent PLEXIGLAS® panels make this possible.

A school of fish just inches away. Taking a walk underwater. A small ecosystem in the middle of a hotel. With modern large aquariums this has become a common sight. Zoos, shopping malls, hotels and amusement parks all want to give their visitors a very special experience. For these spectacular projects, the materials have to fulfill very specific requirements. For example, the panels have to allow for large formats, be formable and still offer a natural view of the animals.

Enter the underwater world: A tour of the Den Blå Planet in Copenhagen. ©Youtube/Fishing with Rod

Just like at the Den Blå Planet in Copenhagen. In Northern Europe’s largest aquarium, visitors can take a tour of underwater regions all around the world. Several thousand animals, including 1000 Piranhas, live there in about 50 aquariums. Separated from the animals by only a 125 millimeter thick PLEXIGLAS® panel, visitors can watch them devour their food with their razor-sharp teeth. “At that sight, you quickly forget that you are standing in front of an aquarium,” says Zac Gill, business development manager at Advanced Aquarium Technologies (AAT),“ and that is what makes the quality of a good aquarium; that its content is displayed vividly.”

Experts on the construction of large aquariums

AAT has been designing and constructing impressive aquariums around the world for over 20 years, and each one of them has its very own requirements. “The design is primarily determined by the spatial conditions, the number of visitors expected and the size of the investment,” says Gill. For this reason, AAT does not produce standard aquariums, each one of their aquariums is unique.

A new challenge every time

However, materials that fulfill the high-quality standards at AAT are a prerequisite for all projects. “In the end, the most important part concerning aquarium panels is that they are invisible,” explains Wolfgang Stuber, specialist for specialty glazings at PLEXIGLAS®. The brand acrylic is absolutely colorless and does not distort the image. “This allows you to see animals underwater as they really are, in the right colors and proportions, without cloudiness,” explains Stuber. At the same time, the panels have to withstand enormous water pressure and are not allowed to bend, let alone break. “PLEXIGLAS® can be produced with a thickness of up to 180 millimeters, which means the pressure of the water is no problem,” says Stuber.

Evolution in Acrylics is our Passion

This topic is a fine example of what “Evolution in acrylics is our passion” – the vision of Evonik’s Acrylic Products business unit – expresses, and what Evonik means by smart concepts in the chemical business. Read more about why evolution is part of the DNA of PLEXIGLAS®, why passion is so important in new projects, and how Evonik’s expertise will advance the development of this material in the years to come.

Larger formats for larger aquariums

Individual PLEXIGLAS® blocks can be bonded together for even stronger parts or larger formats. Here, vertical seams remain invisible, but horizontal formats are limited in their scope. Due to refraction of light, the seams of two horizontally bonded blocks would be visible. “This means the construction of aquariums is currently limited to a certain height,” says AAT’s expert Zac Gill. The industrial standard is currently about 8.30 meters. In order to make even larger formats possible, AAT has recently started cooperating with Evonik and now produces blocks in a format of up to 12 meters as a licensed partner. “We are convinced that we have to take this step to push the boundaries of aquarium construction even further,” says Gill.

Quality, important for profitability

The costs for such spectacular aquariums can quickly amount to sums of over tens of millions. Therefore, longevity plays an important role when selecting suitable materials. “Because aquariums deal with millions of – typically salty – water you really need to consider the life of the materials used,” explains Gill. “We have seen aquariums built with cast iron valves in salt water systems and these rust out in one year and all parts need replacing. Thus, high quality materials are very important for the ongoing operating costs and profitability of aquariums.” Original PLEXIGLAS® not only stays transparent for several decades, it is also insusceptible to salt water, as Gill confirms from his work experience: “We undertook a refurbishment on an aquarium in New Zealand which was the first acrylic tunnel to be installed 31 years ago, and for this they used PLEXIGLAS®. The tank was drained completely and we removed the tunnel panels and after a quick resize and a polish they looked as good as the day they went in.”