Glass vs. Acrylic Aquariums

The Disadvantages of Glass Can be Engineered around — Acrylic’s Fatal Flaws Cannot

Acrylic is often popular with manufacturers and hobbyists because it’s lightweight and relatively easy to fabricate. To cut and manipulate heavy sheets of glass, there’s a large investment in tooling, equipment, and engineering. The lower cost to produce is why many aquarium manufacturers use acrylic, not because of structural or clarity benefits.

Many hobbyists and small manufacturers can create custom aquariums with very simple and inexpensive equipment. However, the end product is not so durable, and the material is very expensive.

Below is a chart that compares the haves and have-nots of both materials.

Glass Aquariums Acrylic Aquariums
Ridged Panels
Free of Fabrication Flaws
Resists Absorption of Chemicals
UV Safe/Won’t turn yellow
No Visual Distortion
Curved Panels

Why We Prefer Glass to Acrylic

In the infancy of our aquarium service division (Serenity USA), we spent a great deal of time researching which material was best.

Overall, we prefer glass to acrylic. We found that you often sacrifice the long-term benefit of glass in exchange for the short-term benefit of acrylic.

Our goal at Custom Aquariums is to mitigate the disadvantages of glass aquariums through our fabrication, moving techniques, and ultra-clear material options.

Regular clarity vs ultra-clear glass

Acrylic Aquariums Scratch Easily

At the end of the day, acrylic is a type of plastic. Take as many precautions as you want using so-called, “acrylic friendly” scrapers and scrubbers, but all it takes is one mishap to have scratches all over. Glass aquariums can scratch, but they have a much higher resistance.

Over the long haul, acrylic aquariums will look old and beat up at a much higher rate than glass aquariums. Unlike a reptile cage where you can swap out the scratched acrylic panels, there is no practical way to fix a severely scratched acrylic aquarium.

You can buff acrylic scratches, but you’ll have to drain your fully established tank. You may also introduce a series of chemicals/buffing compounds that can be dangerous to your fish. And, even when buffing scratches out, it’ll be very tough to return it to its original clarity.

Acrylic Aquariums Are Prone to Fabrication Flaws

Since acrylic is flexible and non-rigid, the tank’s design and the welding quality are critical to its integrity; much more so than fabricating a glass aquarium that has rigid panels.

When welding the joints of an acrylic tank, even the slightest oversight can lead to air bubbles in a joint, compromising the integrity of the entire tank.

Since glass panels are much more rigid, the joints don’t need to be quite as perfect as an acrylic tank. In the long run, it is far less probable that a glass aquarium fails compared to an acrylic one.

Acrylic Aquariums Become Yellow and Brittle Over Time

Another inherent flaw of acrylic is it can’t stand up to UV light, turning yellow over time. Many plastic materials claim to be “UV Resistant”, but no acrylic is UV-proof.

In the long run, no additive can make plastic/acrylic stand up to UV light as long as glass. The elements will eventually get to it.

Think of an old faded billboard… The billboard was likely printed on UV-resistant vinyl. It may have held up for 5 years instead of 6 months, but eventually, it will fade and become brittle.

When an acrylic aquarium starts to break down because of UV light, either from the sun or aquarium lights, it will turn yellow, become brittle, and even crack and fail. The more UV lights you have on your tank, or the closer it is to a window, the more accelerated this process will be.

Acrylic Aquariums Have Porous Material

Many people don’t consider acrylic to be a porous material because containers that hold water are made of it, right? This is true, but although water does not visibly pass through acrylic, it is still absorbed by it and slowly leaches out the other side.

What that also means is the various chemicals and bacteria found in the tank or the outside air, may deteriorate the acrylic and fester at the microscopic level.

Think about a plastic container that has sat outside for years… UV light has taken its toll, and the chemical elements are impregnated in the material, changing its composition forever. A pane of glass, however, can endure the elements for generations. After a good cleaning, it will come back to nearly its original condition.

Acrylic Aquariums Have Greater Visible Distortion than Glass Aquariums

Clarity can vary a lot depending on the grade and brand used by the manufacturer, so it’s important to know the exact clarity you’re getting.

Second, because acrylic panels are so flexible, the acrylic can bow significantly in the middle, which creates visible distortions. Larger acrylic fish tanks have to be made of very thick and expensive panels to prevent this. Unfortunately, acrylic this thick is often prone to impurities, making it less clear.

The third reason is the general quality of the fabrication. Because the strength of an acrylic aquarium relies heavily on the weld rather than the rigidity of the panel, a great deal of the strength and potential distortion is placed on the weld. This makes human error a much more significant factor.

Glass aquariums, on the other hand, are very rigid and come from the factory perfectly flat with extremely tight manufacturing tolerances.

Distortion has more to do with the refractive light coming off the water in the tank (which you will get regardless of the material you use). And if ultra-clear is what you are looking for, we do offer ultra-clear glass for any panel for an extra charge.

This has more to do with clarity than distortion. Ultra-clear glass aquariums are made with less iron and therefore are slightly more transparent and clear than standard glass aquariums.

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