How to Choose the Right Glass Thickness for a Custom Fish Tank

Picking the right glass thickness is super important because it keeps your aquarium strong, safe, and long-lasting. If the glass is too thin, your tank might crack or break. If it’s too thick, you might be spending extra money unnecessarily. In this guide, we’ll break it down in simple words so you can make the right choice for your aquarium!

Why is Glass Thickness Important for an Aquarium

A fish tank holds a lot of water, and that water creates pressure on the glass. If the glass is too thin, it may bow, crack, or even burst. Choosing the right thickness ensures:

• Tank strength – Prevents cracks & leaks.

• Safety – Avoids accidents & fish loss.

• Better clarity – Thicker glass reduces distortion.

• Longevity – A properly built tank lasts years without issues.

Types of Glass Used in Aquariums 

Before choosing the thickness, you need to understand the types of glass commonly used in fish tanks:

1. Standard Float Glass (Normal Glass) 

• Most common type used in budget aquariums.

• Strong but can shatter into sharp pieces if broken.

• More affordable than extra-clear glass.

  
  

2. Low-Iron Glass (Ultra Clear Glass) 

• Also called extra-clear glass or crystal-clear glass.

• Has less green tint and looks premium.

• More expensive but gives better visibility.

  
  

3. Tempered Glass (Super Strong Glass) 

• 5x stronger than normal glass.

• Shatters into small, non-sharp pieces if broken.

• Can’t be cut or drilled after it’s made.

How to Choose the Right Glass Thickness

The bigger your tank, the thicker your glass should be! Here’s a quick guide based on tank size:

Tank Size (L x W x H)	Recommended Glass Thickness
24" x 12" x 12" (37-56 liter)	6mm (1/4 inch)
36" x 18" x 18" (113-151 liter)	8mm (5/16 inch)
48" x 24" x 24" (189-378 liter)	10mm (3/8 inch)
60" x 24" x 24" (378-567 liter)	12mm (1/2 inch)
72" x 30" x 30" (567-946 liter)	15mm (5/8 inch)
96" x 30" x 30" (946+ liter)	19mm (3/4 inch)

🔹 For rimless aquariums (without top bracing), always go 1-2mm thicker for extra strength.

🔹 For extra safety, always go slightly thicker than the minimum recommended thickness.

Glass vs. Acrylic: Which One is Better

Some people also consider acrylic for their aquariums. Let’s quickly compare the two:

Feature	Glass	Acrylic
Strength	Strong, but can crack	More impact-resistant
Weight	Heavy	Lightweight
Scratch Resistance	Hard to scratch	Scratches easily
Clarity	Very clear	Can yellow over time
Cost	More affordable	More expensive

1. If you want a sturdy, scratch-resistant tank, go for glass.

2. If you need a lightweight, custom-shaped tank, acrylic is a good option.

   
   

Factors That Affect Glass Thickness 

When choosing the right glass thickness, consider these important factors:

✔ Tank height – Taller tanks = more pressure = thicker glass needed.

✔ Bracing (Support Frames) – Braced tanks can use slightly thinner glass.

✔ Water type – Saltwater tanks may need thicker glass due to extra weight from corals & rock.

✔ Fish type – If you keep monster fish like Arowanas or Stingrays, go for thicker glass to handle their movements.

Common Mistakes to Avoid

• Using thin glass for large tanks – This is a recipe for disaster! Always use the right thickness.

• Ignoring rimless tank requirements – No bracing means you need thicker glass.

• Choosing cheap, low-quality glass – Always go for good-quality glass from a trusted supplier.

• Not sealing edges properly – Use high-quality aquarium silicone to prevent leaks.

  
  

Choosing the right glass thickness for your custom fish tank is super important to ensure safety and durability.

Best for small tanks? → 6mm-8mm glass is enough.

Best for medium tanks? → 10mm-12mm for safety.

Best for monster tanks? → 15mm-19mm for long-term durability.