Aquarium glass can be either tempered or annealed (standard) depending on the panel and the manufacturer. Most front, side, and back walls are annealed glass, which allows them to be drilled or cut. The bottom panel of larger tanks is frequently tempered for extra strength.
Check for a Tempered Stamp or Etching
Tempered glass often has an etched logo in one corner. This mark may include the manufacturer's name and safety code (e.g., “Tempered,” “ANSI Z97. 1,” or “CPSC 16 CFR 1201”). If you can't find a stamp, move to the next method — some older glass may lack visible labels.
Tempered glass is not suitable for aquarium use. Because it is designed to shatter on impact rather than simply crack it would mean total disaster if an aquarium made from it should be damaged: the entire tank would shatter into fragments and all fish would be lost (along with the water).
Float glass, also known as ordinary glass, is the basic material used for most aquariums. Its sodium and calcium silicate composition provides desirable transparency and strength.
To quickly determine if glass is tempered, check the corners for a permanent manufacturer's stamp (etched or baked on) and feel for smooth, polished edges. If the stamp is missing, view the glass through polarized sunglasses under a bright light or at the sky; tempered glass will show shadowy lines or spots.
Tempered glass cannot be cut. It will shatter into tiny pieces.
The short answer is yes, all toughened safety glass must be stamped or marked. In this blog, we'll explain why that is, what the stamp means and how standards like BS EN 12150 ensure your glass is safe, compliant and fit for purpose.
As the name implies, aquarium glass is basically a special type of glass that is meant to be used in fish tanks. As the fish tanks typically have multiple gallons of water storage, the glass used in aquariums must be strong enough to hold it.
Tempered glass is fine. The bottoms of most aquariums are tempered. And alot of aquariums on the larger side are tempered which is part of the reason why larger tanks are more expensive usually because they use tempered glass.
Glass aquariums are prone to leaks and breakage, often caused by sealant failure or improper construction.
However, acrylic aquariums can scratch more easily. So if you notice lots of little lines on the surface, you'll know it's an acrylic type. Even though glass is less durable, it's very scratch resistant. You won't have to worry about damaging your tank with various decorations or during cleaning.
A tempered glass window can be identified by the “bug” or white etched label at one corner of the window.
Yes, fish absolutely recognize their owners! While it is based on conditioned feeding responses rather than emotional affection, scientific research shows they can distinguish human faces and learn your daily routines.
To quickly distinguish tempered glass from regular glass, look for a permanent manufacturer's logo or "Tempered" stamp near one of the corners. If it’s unstamped, you can test it by putting on polarized sunglasses and looking at a bright screen or the sky through the glass—tempered glass will display dark, shady spots or lines (stresses from the tempering rollers).
Acrylic is often preferred over glass because it's lightweight, cheaper to produce, and can take on different shapes. We argue that, while these factors are important to the manufacturer and the customer, glass fish tanks offer more durability, clarity, and longevity than acrylic ones.
Scratch the glass with a hard object like a key. If the scratch feels smooth, the glass is tempered. An untempered glass scratch will feel sharp and gritty. The tempering process also makes the glass surface much harder to scratch or damage.
For the best balance of structural safety, scratch resistance, and crystal-clear viewing, Low-Iron glass (also known as Starphire or Opti-Clear) is the gold standard. It removes the natural green tint found in standard glass, offering pristine clarity to showcase your aquascape.
While tempered glass offers enhanced strength, it has limitations in terms of adaptability after manufacturing. It cannot be cut or drilled, requiring precise pre-manufacturing measurements. Additionally, it can occasionally suffer from spontaneous breakage due to nickel sulfide inclusions.
Yes, fish can hear music. They do not have outer or middle ears like humans, but they have internal "ear stones" (called otoliths) and a lateral line that detect sound waves and vibrations in the water. Sound actually travels about five times faster underwater than in the air.
Float glass is the standard material for the production of glass aquariums.
Acrylic is a very popular material for aquariums because it is lightweight but strong and has good optical clarity. Compared to glass, acrylic is much stronger and less likely to shatter. Acrylic is also more impact-resistant than glass, and it's harder to break when exposed to accidental impacts or vibrations.
To quickly determine if glass is tempered, check the corners for a permanent manufacturer's stamp (etched or baked on) and feel for smooth, polished edges. If the stamp is missing, view the glass through polarized sunglasses under a bright light or at the sky; tempered glass will show shadowy lines or spots.
Yes, tempered glass is significantly stronger than regular glass. It is about four to five times stronger and can withstand much higher impacts and heat.
Tempered glass is more expensive than standard glass due to the additional processing, but it's generally affordable for most projects. It offers long-term value thanks to its safety features, durability, and compliance with building codes.