Acrylic vs Glass Aquarium: Which Should You Choose?

Table of Contents

• Introduction
• Material Basics: Glass and Acrylic
• Key Buying Criteria
• Detailed Comparison
• Clarity and Aesthetics
• Durability and Scratch Resistance
• Weight and Handling
• Shaping and Customisation
• Cost Analysis
• Singapore Availability and Buying Tips
• Best Use Cases for Each Material
• Frequently Asked Questions
• Conclusion

Introduction

The acrylic vs glass aquarium debate is one of the most common discussions in the fishkeeping and aquascaping community. Both materials have been used for decades to build stunning aquariums, yet each has distinct properties that make it better suited for certain applications. Whether you are setting up a small desktop nano tank or planning a large showpiece aquarium for your living room, understanding the differences between these two materials is essential.

At Gensou, located at 5 Everton Park in Singapore, we have over 20 years of experience working with both glass and acrylic tanks. In this comprehensive guide, we will walk you through every factor you need to consider so you can make an informed decision for your next aquarium purchase.

Material Basics: Glass and Acrylic

Glass Aquariums

Most aquarium glass is standard float glass, which is manufactured by floating molten glass on a bed of molten tin to produce flat, uniform panels. Higher-end tanks use low-iron glass (sometimes marketed as ultra-clear or Starphire glass), which has reduced green tinting for superior optical clarity. Panels are joined using silicone sealant.

Acrylic Aquariums

Acrylic, also known as polymethyl methacrylate (PMMA) or by brand names such as Plexiglas and Perspex, is a thermoplastic that can be moulded, bent, and bonded using solvent welding. Acrylic aquariums are typically formed from cast acrylic sheets that are chemically bonded at the seams, creating a nearly invisible joint.

Key Buying Criteria

When deciding between an acrylic vs glass aquarium, evaluate the following criteria based on your specific needs:

Detailed Comparison

The table below provides a comprehensive side-by-side comparison of glass and acrylic aquariums across all major categories.

Clarity and Aesthetics

Optical clarity is often the first thing aquarists consider. Standard float glass has a slight greenish tint, particularly noticeable on thicker panels and when viewed from the edge. Low-iron glass eliminates most of this tinting and is the preferred choice for high-end aquascapes where colour accuracy matters.

Acrylic, by contrast, transmits approximately 93% of visible light — slightly more than standard glass. It produces minimal colour distortion and, when new, offers outstanding clarity. However, acrylic is prone to fine surface scratches that can accumulate over time, creating a hazy appearance if not maintained carefully.

Aesthetic Considerations

• Silicone seams – Glass tanks have visible silicone joints at corners. While black silicone can look clean, some hobbyists prefer the near-invisible bonded seams of acrylic.
• Panel thickness – For the same water pressure, acrylic panels can be thinner than glass, giving a more delicate, refined appearance.
• Yellowing – Lower-quality acrylic can yellow with prolonged exposure to light. UV-stabilised acrylic resists this effect but costs more.

Durability and Scratch Resistance

This is where the acrylic vs glass aquarium debate becomes most heated. Glass is significantly harder than acrylic, rating around 5.5 on the Mohs scale compared to acrylic’s approximately 3. This means glass resists scratches from algae scrapers, gravel, and general handling far better than acrylic.

However, acrylic’s softness is also its strength in terms of impact resistance. A glass tank struck by a heavy object may crack or shatter catastrophically, whereas acrylic will flex and absorb the impact. For households with young children or in areas where accidental impacts are a concern, acrylic offers a meaningful safety advantage.

Scratch Repair

One advantage of acrylic is that scratches can be polished out using progressively finer grades of wet-and-dry sandpaper followed by a plastic polish compound. Glass scratches, while rarer, are essentially permanent. This repairability means that a well-maintained acrylic tank can be restored to near-original clarity even after years of use.

Weight and Handling

Acrylic is approximately half the weight of glass for the same dimensions. This difference becomes particularly significant with larger tanks:

In Singapore, where many hobbyists live in HDB flats or condominiums with lift access, the lighter weight of acrylic can make a substantial difference during delivery and installation. It also reduces the load on your aquarium stand and the floor structure beneath it.

Shaping and Customisation

Acrylic is the clear winner when it comes to custom shapes. It can be heated and bent into curves, formed into cylinders, or moulded into virtually any shape. This makes it the preferred material for bow-front tanks, L-shaped tanks, cylindrical columns, and other non-standard designs.

Glass, while it can be curved (curved glass panels do exist), is far more expensive to produce in non-flat shapes. Most glass aquariums are rectangular or cube-shaped. Low-iron curved glass panels are available but command a significant premium.

Cost Analysis

For standard rectangular tanks up to about 120 cm, glass is typically the more affordable option. The raw material cost of glass is lower, and manufacturing processes for flat-panel glass tanks are well-established and efficient.

However, the cost equation shifts for very large tanks (over 150 cm). At these sizes, glass panels become extremely heavy, requiring thicker material and more robust support structures. Acrylic can often be more cost-effective for large custom builds, as the material is easier to work with at scale and the lighter weight reduces structural requirements.

Singapore Availability and Buying Tips

Singapore has a thriving aquarium market with options for both glass and acrylic tanks:

• Glass tanks – Widely available at local fish shops across Singapore, particularly along the Serangoon North corridor and at Qian Hu’s retail outlet. Low-iron glass tanks from brands popular in the region are readily stocked.
• Acrylic tanks – Less commonly stocked off the shelf but available through custom fabricators. Several workshops in the industrial areas of Tuas and Woodlands specialise in acrylic aquarium construction.
• Custom builds – For non-standard sizes or shapes, getting a custom tank built locally is often more cost-effective than importing, as you avoid shipping fragile large panels.
• Climate consideration – Singapore’s consistently warm temperatures mean thermal insulation is less of a differentiating factor, though acrylic’s slightly better insulation can marginally reduce chiller energy consumption for cold-water setups.
• Humidity – High ambient humidity in Singapore does not significantly affect either material, but ensure silicone sealant on glass tanks is of marine-grade quality to resist degradation.

Best Use Cases for Each Material

Choose Glass If:

• You want a standard rectangular or cube tank
• Scratch resistance is a priority (especially with algae-eating fish or frequent cleaning)
• You are working with a tighter budget for standard-size tanks
• Long-term clarity without yellowing is important
• You plan to use magnetic algae cleaners regularly

Choose Acrylic If:

• You need a large tank (over 150 cm) where weight is a concern
• You want a curved, bow-front, or custom-shaped aquarium
• Impact resistance and safety are priorities
• You need to drill the tank for plumbing (sumps, overflows)
• The tank will be installed in an elevated position where weight matters
• You prefer seamless, bonded joints for a cleaner look

Frequently Asked Questions

Does acrylic yellow over time?

Lower-quality acrylic can develop a yellowish tint after prolonged exposure to UV light. However, modern UV-stabilised acrylic is specifically formulated to resist yellowing. When purchasing an acrylic tank, always confirm that UV-stabilised material has been used, particularly if the tank will be placed near windows or under strong lighting.

Can I use a razor blade to clean algae off an acrylic tank?

No. Razor blades and metal scrapers will scratch acrylic almost immediately. Use only soft plastic scrapers or microfibre pads designed for acrylic surfaces. Magnetic algae cleaners with acrylic-safe pads are also available and work well for routine maintenance.

Which material is better for a reef aquarium?

Both materials work well for reef aquariums. Glass is more popular for small to medium reef tanks due to its scratch resistance and the widespread availability of low-iron glass. Acrylic is often preferred for very large reef systems where weight reduction and custom shapes (such as peninsula-style tanks) are desirable. The choice ultimately depends on your specific setup requirements and budget.

Is it true that acrylic tanks have better clarity than glass?

Standard acrylic transmits slightly more visible light than standard float glass. However, low-iron glass offers clarity that rivals or exceeds acrylic while also being far more scratch-resistant. For the very best optical experience, low-iron glass is generally the top choice for serious aquascapers.

Related Reading

• Best Acrylic Polish Kits for Aquarium Scratch Removal
• Best Acrylic Aquarium Repair Kits
• Best Acrylic Aquarium Scratch Repair Kits and Methods
• Best Algae Magnets for Acrylic Aquariums
• Best Algae Scrubber Pads for Aquarium Glass Cleaning

Conclusion

The acrylic vs glass aquarium decision ultimately comes down to your specific needs, tank size, budget, and aesthetic preferences. Glass excels in scratch resistance, long-term clarity, and affordability for standard sizes. Acrylic shines when you need lightweight construction, custom shapes, impact resistance, or very large tanks.

At Gensou, we work with both materials and can help you determine the best option for your particular project. With over 20 years of experience in Singapore’s aquascaping scene, we understand the practical considerations that matter most in our local context.

Need help choosing the right aquarium? Contact our team for expert guidance tailored to your space and budget. Explore our shop for a curated selection of quality tanks, or discover our custom aquarium service for a bespoke build designed exactly to your specifications.