When choosing between acrylic and glass aquariums, each material has its own strengths depending on your needs, budget, and how you plan to use the tank.
Here’s a breakdown of the advantages of acrylic versus glass:
Advantages of Acrylic Aquariums
Lightweight: Acrylic is about half the weight of glass—sometimes even less. A 50-gallon acrylic tank might weigh 20-25 pounds empty, while a glass one could be 50-60 pounds. This makes it easier to move or set up, especially for larger tanks.
Stronger and More Impact-Resistant: Acrylic is 10-20 times more shatter-resistant than glass. It flexes slightly under pressure instead of cracking, so it’s less likely to break if bumped or dropped (handy if you’ve got kids or pets).
Custom Shapes: Acrylic can be molded into curves, bows, or even seamless cylindrical designs—glass is usually limited to flat panels glued together. Want a funky hexagonal or rounded tank? Acrylic’s your pick.
Better Clarity: Acrylic has higher optical clarity (around 92% light transmission vs. glass’s 89-91%). It doesn’t have the slight greenish tint some glass (especially thicker panes) can show, giving a crisper view of your fish.
Insulation: Acrylic retains heat better than glass, which might save a few bucks on heater costs in colder climates, though the difference is small unless the tank’s huge.
Easier to Drill: Need to add custom plumbing or overflows? Acrylic can be drilled and modified with basic tools, while glass often requires special diamond bits and more skill (or pre-drilled panels).
Advantages of Glass Aquariums
Scratch Resistance: Glass is much harder than acrylic—think 5-6 on the Mohs scale versus acrylic’s 2-3. Acrylic scratches easily from cleaning tools, algae scrapers, or even coarse substrate, while glass holds up better over time.
Cheaper: Glass tanks are usually more affordable, especially for standard sizes. A 20-gallon glass tank might cost $30-50, while an acrylic one could run $80-120. The price gap widens with bigger tanks.
Durability Over Time: Glass doesn’t yellow or cloud with age like acrylic can (especially cheaper acrylic exposed to UV light or harsh cleaners). A well-maintained glass tank can look new for decades and be easily resealed with silicone. After 30-40 years plastic frames can become brittle and simply removed.
Widely Available: Glass tanks are still available new and secondhand options are plentiful.
Chemical Resistance: Glass won’t react to aquarium-safe cleaners or medications. Acrylic can craze (form tiny cracks) if exposed to alcohol, acetone, or certain chemicals by mistake.
Less Bowing: Thick glass resists bowing under water pressure better than acrylic. Large acrylic tanks (over 100 gallons) need thicker walls or bracing to avoid bulging, adding cost and weight.