Does Aquarium Tank Glass Need to be Tempered? (2022)

Does Aquarium Glass Need to be Tempered?

Once you get above the size of tabletop aquariums, you find they contain a considerable amount of water. Once you add this up, you wonder how glass can hold such weight.

Even a 5-gallon tank contains 41.7 pounds of water, and that is with no gravel decorations and fish. Stronger glass has to be the answer.

Does aquarium glass need to be tempered? To your surprise, you will find, there is no reason any fish tank has to be made from tempered glass. If you see aquariums made from tempered glass, they are more than likely commercially produced, and it is a cost-cutting exercise where they use thinner tank glass than is recommended.

How Thick Should Aquarium Glass Be?

If you ever consider making your own, or you are on the market for any aquarium, there are elements to the glass you should know. While glass doesn’t have to be tempered, you can have other factors affecting your tank.

No tank maker would ever consider using tempered glass. Rather, they would want to use the correct thickness. You find this thickness relates to the height of your tank.

From a safety point of view, no glass used will have a safety factor of 3.8 based on the tank height.

However, the recommended thicknesses are 0.75 of an inch (19mm). This size is more common than the actual safety thickness, which is 0.67 of an inch or 17 mm and isn’t common.

Glass Thickness and Bonding

If you have the same design tank, yet in varying sizes, the only things that ought to differ are the bonding of the glass and its thickness. The larger the tank, the better your bonding has to be.

With this, the thickness of your glass has to be suitable to hold such a volume of water.

One area a few tank owners overlook is that there are some instances where the glass is suitable to hold a given amount of water, yet there is no margin of error. If your tank receives a knock, bang, or scratch, this can be enough to shock it into breaking.

When they produce glass, manufacturers use tensile strengths in mega-pascals. On this scale, you see the measure of the force of pressure can generate. Such tensile strengths range from 19.3 to 28.4 mega pascals.

The safety factor is added in, and this is where you get the 3.8 coming into play. It is this that removes any risk of glass failure unless it is poor quality, or you have scratches or chips that weaken your glass. You can find glass calculators online.

Tank Construction

Another area some tank potential tank owners overlook is the size of the tank to the glass thickness. You can’t have the right thickness and assume any length of tank will work.

Many fish lovers have 55-gallon tanks which often measure 4 feet by 15 inches. For this size, use glass that’s quarter of an inch thick. You may see on glass safety charts; this will come with a safety factor of 2.92.

Tank Construction

Should you wish to change the safety factor from the chart, you need to use thicker glass, or you can off-set the difference.

If you brace the center of the tank with a four-inch-wide piece of glass, you will off-set this shortage and raise the safety factor to 3.38.

Aquariums you ever see sitting on Styrofoam may use thinner glass, as this is one way to get around it. The Styrofoam or polystyrene spreads the point of load between your tank and the tank stand.

Glass Vs. Acrylic

With fresh materials, some tank builders may opt to use acrylic as their material. The choice of aquarium material is important, depending on the type of water you will be using.

Here we will look at the advantages of glass and acrylic for your fish tanks.

The material most commonly employed material used in aquarium construction is glass. Glass is manufactured when they heat regular sand, which mainly comprises silicon dioxide to temperatures of 1700 degrees Celsius (3090F).

Once it hits these temperatures, sand liquefies, and it then gets poured across tin plates to form panes of clear glass. It is when the material cools; it turns into the material we know.

If you see standard glass from the end of the pane, you can see a little aqua and green hue, though you can get other clear glass.

Glass low in iron content is this clear glass and often sent to market as ‘Starphire’ glass.

Advantages of Glass


For most small or medium-sized aquariums with a water capacity of fewer than 200 gallons, you can find glass offers a cost-effective solution.

Scratch resistance

The material has a low tendency to scratch from most other materials. You will find this very conducive to effective cleaning. You can now use many tools and implements to keep tanks clean.

Advantages of Glass

Since scratching is not a major problem, metal blades are a convenient, extremely effective tool to eliminate algae from the inside of your aquarium panes.

If you take care not to harm the silicone seals, you can use razor blades with tremendous results.

Glass Discoloration

Through time, you can find that glass will not discolor or ‘yellow,’ as some other acrylic materials are likely to do.

It is important to remember, however, that conventional glass introduces a blue tint to the appearance, which you can notice more in thicker panes of glass. Starphire glass offers a more colorless solution.

Sadly, glass has several other potentially important drawbacks.

Disadvantages of Glass


When you compare the weights of glass to acrylics, you can find the weight is almost double. For large aquariums, this poses problems with seating the tank and also transportation.

Tanks that exceed 100 gallons volume of water will exceed 200 lbs. of dry weight. You can find that aquariums around 180 gallons of water quickly rise to over 300 lbs. dry weight.

Anyone with a custom aquarium that lacks plastic braces and opts to use glass braces, you can find the weights even heavier.

Limited Shapes and Size

When you compare the flexibility of glass to acrylic, the glass will be very limited in terms of the shape and size you can make your aquarium. It will be truer should you desire a custom aquarium where your glass is custom manufactured.

Benefits of Acrylic

Gaining in popularity is the construction of custom-built acrylic aquariums.

It is good to understand the meaning of acrylic for aquarium use. The word “acrylic” is not just one unique material, and there are several variations. Acrylic is often called “poly acrylate,” which is just one common form of acrylic.

Manufacturers use two simple classes of molecules, methyl methacrylate or poly methyl methacrylate, to produce acrylic. When used as an aquarium building material, acrylic has many obvious advantages.

Some of the more common brand names you may recognize for poly methyl methacrylate acrylic can include:

  • Plexiglass and Lukitis
  • Perspex and Crystallite
  • Advantages


Acrylic is considerably lighter than glass so that aquariums can save weight at least 50% compared to glass. You can achieve this while preserving your aquarium’s power and integrity.

Benefits of Acrylic


In comparison, you will find acrylic is around seventeen times stronger than glass when it has the same dimensions. Not only will it be lighter, yet you can use a smaller measurement or thickness compared to glass, and still gain benefits from significant weight decreases.

Joints of acrylic panels will be chemically adhered or fused. From this, you will get levels of strength and durability that a glass aquarium cannot match with silicone seals alone.

Easy to Customize

Since you can mold acrylic into any shape or form, you can easily build aquariums of unique shapes and sizes. It will, however, depend on the type of acrylic you’re using.

The need for custom aquarium builders with glass can be negated. It is possible to build or modify existing aquariums with the use of basic tools you can find in many a home workshop.

Although acrylic is packed with benefits, you still find it has some drawbacks.

Disadvantages of Acrylic


The primary downside of acrylic in aquarium manufacture is that they can scratch very easily. If you take pride in your tank, you’ll understand how upsetting a scratch across the front of your tank would be.

You can use a buffing process to remove some shallow acrylic scratches, unlike glass that would be more permanent.

For cleaning the insides or outsides of your tanks, you will quickly find limitations on the tools you can use. No longer can you use your razor blades to clear algae.


When the glass is a cost-effective material, you have acrylics at the other end of the scale. You can find some Nano-sized aquariums that are quite cheap, yet larger acrylic aquariums are custom made. You can see the market costs for these materials will be reflected in the prices of fish tanks.


Glass remains the same color, and unfortunately, acrylic will yellow over time, which can vary based on the acrylic material you use.

While you may get an acrylic that doesn’t discolor, these are going to be far higher in cost.


Underwater backgrounds, plants and rocks etc. are all to be added, and you can find acrylic aquariums offer fewer access opportunities than you would have with a glass fish tank. Be sure to check your aquarium has access if you are purchasing new or having one custom made.


You can see from all the information here, there is no need to use tempered glass, and doing so can make your tank harder to care for in the long run.

Should you seek another material, you can see the most viable option is acrylic, yet even that poses some problems and restrictions. Plain glass, albeit of the right thickness, will be around as the material of choice for many years. You also find it offers you the best view to look into your underwater world.