How to Tell If a Fish Aquarium Is Tempered-Glass?

Tempered glass is created when glass is heated at extremely high temperatures and then cooled rapidly. The process creates a tough bond among the elements in the material. Common uses for tempered glass include car windows, computer monitors and aquariums. Tempered glass is common in aquarium construction because it can withstand the pressure and weight of the many gallons of water inside the tank. You can use a couple of techniques to determine if your aquarium is made from tempered glass.

Things You'll Need

  • Polarized sunglasses
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Instructions

    • 1

      Look for tempered glass stamps on the corners of your fish tank. Decode the letter underneath the company trademark. The code refers to the type of tempered glass material. An "L" stands for "laminated" and a "T" stands for "toughened." Laminated tempered glass has a layer of window film or tint, while toughened tempered glass means the glass has been heated and cooled rapidly to create a strong glass material. The letter (A, B or C) that follows the "L" or "T" represents the pressure grade of the aquarium. "A" can withstand more weight and pressure than B or C.

    • 2

      Look for bumps and waves in the glass. View the aquarium from a 45-degree angle to look for imperfections caused by the heating and rapid cooling process. If you notice these imperfections, your aquarium is made of tempered glass.

    • 3

      Look for black lines on the tank with a pair of polarized sunglasses. Stand on the side of the aquarium and look across the glass at a 45-degree angle. If the glass is tempered, you see black lines from the heating and cooling process. Put your hand on the front of the aquarium and look through the sides. You should not be able to see your hand through the polarizing glasses and tempered glass.