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---
title: "Materials"
date: 2018-08-13T19:22:34+02:00
draft: false
---
# Materials
Most aquaria consist of glass panes bonded together by 100% silicone sealant, with plastic frames attached to the upper and lower edges for decoration. The glass aquarium is standard for sizes up to about 1,000 litres (260 US gal; 220 imp gal). However, glass as a material is brittle and has very little give before fracturing, though generally the sealant fails first. Aquaria are made in a variety of shapes, such as cuboid, hexagonal, angled to fit in a corner (L-shaped), and bow-front (the front side curves outwards). Fish bowls are generally either made of plastic or glass, and are either spherical or some other round configuration in shape.
The very first modern aquarium made of glass was developed in the 19th century by Robert Warrington. During the Victorian age, glass aquariums commonly had slate or steel bottoms, which allowed them to be heated underneath by an open-flame heat source. These aquariums had the glass panels attached with metal frames and sealed with putty. Metal-framed aquariums were still available until the mid-1960s, when the modern, silicone-sealed style replaced them. Acrylic aquariums first became available to the public in the 1970s. Laminated glass is sometimes used, which combines the advantages of both glass and acrylic.
Glass aquaria have been a popular choice for many home and hobbyist aquarists for many years. Once silicone sealant became strong enough to ensure a long-term water-tight seal, it eliminated the need for a structural frame. In addition to lower cost, glass aquaria are more scratch resistant than acrylic. Although the price is one of the main considerations for aquarists when deciding which of these two types of aquaria to purchase, for very large tanks, the price difference tends to disappear.
An aquarium in the Burj Al Arab in Dubai
Acrylic aquaria are now the primary competitor with glass. Prior to the invention of UV stabilization, early acrylic aquaria discolored over time with exposure to light; this is no longer the case. Acrylic is generally stronger than glass, weighs less, and provides a certain amount of temperature insulation. In colder climates or environments, it is easier to achieve and maintain a tropical temperature and requires less capacity from an aquarium heater. Acrylic-soluble cements are used to directly fuse acrylic together. Acrylic allows for the formation of unusual shapes, such as the hexagonal tank. Compared to glass, acrylics are easier to scratch; but unlike glass, it is possible to polish out scratches in acrylic.
Large aquaria might instead use stronger materials such as fiberglass-reinforced plastics. However, this material is not transparent. Reinforced concrete is used for aquaria where weight and space are not factors. Concrete must be coated with a waterproof layer to prevent the water from breaking down the concrete, as well as preventing contamination of the water by the concrete.
Plywood can also be used when building aquaria. The benefits of using plywood include: lower construction costs, less weight, and better insulation. A popular positioning choice for plywood aquaria is keeping them in a wall. Here the use of plywood is hidden by sinking the aquarium inside the wall. Putting insulation between the two helps with the insulation of a heated tank.
{{% note normal %}}
This drawing have been simplified to understand how it works. It may have difference in reality.
{{% /note %}}
| Number | Denomination |
| ------: | :----------: |
| 1 | Intake |
| 2 | mechanical filtration |
| 3 | chemical filtration |
| 4 | biological filtration medium |
| 5 | outflow to tank |
|
