Tempered glass is a type of safety glass that has been thermally or chemically treated to increase its strength compared to regular glass. A fish tank made from tempered glass is not only stronger but also lighter than one made from non-tempered glass.

However, a major disadvantage of tempered glass is that it’s nearly impossible to drill or reshape once it has been treated. Any holes needed must be drilled before the tempering process, which can significantly increase costs. If subjected to blunt force, tempered glass will shatter into thousands of small pieces, while non-tempered glass is more likely to crack.

Many tropical fish enthusiasts prefer drilling through the bottom of their tanks to install custom overflows or sump filtration systems. In this case, tempered glass may not be ideal. Once the glass is tempered, it cannot be altered, so any customisation must be done prior to tempering. Non-tempered glass is much easier to cut or drill than tempered glass.

Tempered Glass vs Acrylic Tanks

Glass tanks are more common and generally more cost-effective than acrylic tanks. Both glass and acrylic are less prone to yellowing over time and have cleaner edges. However, tempered glass is more likely to yellow with age and can show uneven finishes, warping, or rippling.

Can I Drill a Hole in My Tank?

Drilling a hole into your aquarium is not without risk. It requires special tools, patience, and the correct technique.

Due to the nature of tempered glass, drilling is not an option. Tempered glass is designed to withstand pressure but will shatter into small pieces if drilled, minimising damage to its surroundings.

Aquariums supplied by All Pond Solutions are made from tempered glass, so we do not recommend attempting to drill into these tanks. If you need a sump system, consider using one of our overflow boxes. These provide a great alternative to drilled systems, allowing you to connect a sump system without drilling a hole into your aquarium.

An overflow box offers the added benefit of being removable if you later decide to switch to external filters. It’s not a permanent modification.