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What’s the difference between glass and acrylic aquariums?

So, you finally decided you want to keep pet fish. The first, and probably most important, component is the fish tank. This guide at Aquarium Blueprints will help you determine the appropriate type, shape, size and placement for your fish tanks.

Should I get an acrylic or glass fish tank?

The two main types of fish tanks most frequently used in the aquarium hobby is acrylic and glass. So which of these will suit your style of fish keeping the best? Let’s compare them in different categories.

Pricing

While acrylic fish tanks are more affordable to manufactured when compared to a glass fish tank of similar size, it actually cost more to buy for the end consumer.

One of the reasons for being more expensive is that acrylic aquariums scratch more easily during shipment. This means that shippers need to add in more protection when shipping. Not to mention that manufacturers also have to deal with more returns when compared to the glass alternative.

The other major reason is a concept called economies of scale, which happens when manufacturers can produce at lower costs by increasing the scale of production. Because glass fish tanks are in more demand, companies can make more of them when compared to acrylic. As a result, glass tanks tend to be more affordable that acrylic tanks of similar size as the lowered production costs will lead to lower prices for the end consumer.

Advantage: Glass

Shapes

Most of the glass tanks that are readily available are either straight up rectangle or rectangle with a bow front. On the other hand, acrylic aquariums come in many sizes such as rectangle, rectangle with a bow front, bull nose, flat back hex, hexagon, pentagon, quarter cylinder and half cylinder.

Glass as a material is more fragile and unyielding when compared to acrylic. Thus, it is far more easier to create an unique looking acrylic aquarium due to the strength and flexibility of acrylic.

Advantage: Acrylic

Weight

As a material, glass weighs more than acrylic if the length, width and depth are the same. A glass aquarium is multiple times more heavier than a acrylic aquarium of the same size.

Keep in mind that the fish tank will be heavy regardless once you fill it with substrate, decorations and water. So, in the end, the weight difference is negligible. The only times that the weight should matter is when you are moving an empty aquarium from one location to another.

Advantage: Acrylic

Clarity

For new fish tanks, glass provide a slightly clearer view when compared to acrylic. With that said, the difference will only widen overtime as acrylic is prone to be discolored after being constantly exposed to artificial and natural sunlight. Not to mention that acrylic can also be easily scratched, which hinders your view of the aquarium even more.

Thus, if you want as clear as a view as possible, then getting a glass fish tank is the best choice of the two.

Advantage: Glass

Distortion

The index of refraction is greater between the water and glass surfaces when compared to acrylic surfaces. As a result, the image you get is more distorted when looking at the water through glass as the color, position and size of the fish, plant and other materials are not accurate. The difference only widens the thicker the glass is used to hold water in the aquarium.

The index of refraction between acrylic and water is a lot closer; furthermore, acrylic panels are also a lot thinner when compared to glass panels in fish tanks of similar sizes. These factors lead to better accuracy when it comes to size and color.

With that said, if the acrylic starts to bow out, discolor and may end up having scratches over time, then the image could become more distorted than glass. While new acrylic fish tanks provide more accurate viewing quality than new glass fish tanks in the beginning, acrylic materials will deteriorate even with the upmost care. Thus, we recommend getting a glass aquarium as it provides a more accurate view in the long run.

Advantage: Glass

Scratch Resistance

As we already mentioned above, acrylic surfaces easily scratched as you can leave permanent markings with even the slightest brushes against the fish tanks. These aquariums can easily be damaged during transportation along with regular tank maintenance (such as cleaning algae off the surface and water changes that can send sharp edge substrate torpedoing into the acrylic). Not to mention that fish with sharp teeth or claws can also leave permanent scratches.

While there are polishing kits that will smooth out these scratches on acrylic surfaces, these may not be safe for use inside the aquarium.

While the glass surface can also be scratched, it requires a lot more force to do so using a sharp object at the right angle. In other words, it will be next to impossible to accidentally scratch a glass aquarium through regular maintenance and fish activity.

Advantage: Glass

Crack Resistance

As a material, glass is easier to crack and break when compared to acrylic. With that said, you will need a sharp object and a tremendous amount of force to do so for both surfaces. Glass can also break easier if your fish tank is not leveled and/or the surface it is resting on has sharp objects sticking out causing pressing points.

With proper placement and care, an aquarium that cracks and/or breaks is something you shouldn’t have to worry about whether if it is made or acrylic or glass.

Advantage: Acrylic

Stand Support

As we stated previously, a glass panel is unyielding. As a result, you don’t have to worry about the bottom bowing out. What this means is that you will only need a stand that support the bottom edges of a glass aquarium to ensure that it won’t break from the pressure of the water weight. Of course, you can also use stands that support the entire bottom of a glass tank as well.

Acrylic panels, on the other hand, can easily bend with pressure from the water weight. As a result, you have to support the entire bottom surface of the tank with your stand if you don’t want the fish tank to burst. Furthermore, you might also want to keep an eye on the other panels as well to make sure that they won’t bow out and cause problems.

Keep in mind that both glass and acrylic fish tanks need to be leveled to prevent unnecessary pressure points that could lead to cracking and/or breaking. You can read more about aquarium stands in this guide.

Advantage: Glass

Heat Retention

Acrylic aquariums are better at maintaining the same temperature when compared to glass aquariums as heat won’t dissipate as fast. This is especially important if you decide to keep your fish tank in an area where it can get breezy (such as by the window and doorway leading outside). The heat retention will also help out your aquarium heater as it does not have to work as hard to maintain a constant temperature.

Advantage: Acrylic

Chemical Absorption

As a surface, acrylic is porous, which means that it has many microscopic holes that will absorb chemicals from both inside and outside of the fish tank. This will lead to deterioration of the panels, resulting in distortion of the image and even breakage of the aquarium.

Owners of glass fish tanks don’t have to worry about any chemical absorption as the surface of the panels are completely solid.

Advantage: Glass

Availability

Glass aquariums are more readily available when compared to acrylic aquariums. This is due to a lot of factors we already mentioned above such as costs, ease of shipment and build quality. So, even if you do decide to get an acrylic fish tank, you may have a hard time finding one from your local fish store.

Recap

Glass fish tanks have the advantage when it comes to pricing, clarity, being less distorted over the long run, more scratch resistant, requiring less support from an aquarium stand, resistant to chemical absorption as well as being more readily available.

Acrylic fish tanks come in more variety of shapes, are easier to move when empty, harder to crack and better at retaining water heat.

The decision is ultimately up to you as to whether or not you think glass of acrylic tanks are best for your needs. If you have a hard time deciding, then we recommend getting glass aquariums as they are more affordable, easier to find and have better build quality when compared to fish tanks built with acrylic panels.