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How Long Do Fish Tanks Last? – Average Lifespan

how long do fish tanks last

The answer to the question of how long do fish tanks last varies across several factors. For example, glass fish tanks can last two decades, while acrylic versions have a shorter lifespan of five to fifteen years.

Temperature changes, material quality, sealant type, aquarium stand stability, fish tank level, and other factors can influence the lifespan of a fish tank.

Continue reading to learn the truth about fish tank longevity.

Table of Contents

How Long Do Acrylic Fish Tanks Last?


Despite their higher price, many aquarists prefer acrylic aquariums because they are more resistant to impact forces. They are also 10 times lighter than glass, allowing aquarium hobbyists to relocate their fish tanks effortlessly.

So, how long do acrylic aquariums last?

If you are picky about your choices and observe a strict fish tank maintenance regimen, you could see your acrylic aquarium lasting 5 to 15 years. Some aquarists can extend the acrylic fish tank’s lifespan to two decades.

Acrylic fish tank panels feature transparent thermoplastic materials (i.e., Plexiglass) bonded together to form a singularly cohesive unit. Industrial-grade acrylic cement facilitates Plexiglass merging by softening the surface, making it easier to shape the tank without damaging its structural integrity.

We can consider acrylic as a solid mesh of plastic fibers, giving it strength and resistance against cracking and breaking. However, the material is prone to scratching and discoloration, resulting in a shorter lifespan overall.

Pros & cons


  • Ten times lighter than glass fish tanks
  • Easier to “mold,” “shape,” or “modify” according to the aquarist’s specifications
  • Higher impact resistance than glass
  • Available in various shapes, including curved
  • More expensive than glass
  • Not scratch-proof and tends to yellow (oxidize) over time
  • Shorter lifespan

What is the Average Lifespan of a Glass Aquarium?


Some aquarists prefer glass over any form of plastic, including acrylic. Glass has a natural charm like leather and wood that no other material can match. However, their designs are not as diverse as acrylic.

So, how long will a glass aquarium last, given its poor impact resistance?

Most glass fish tanks last two decades, depending on several factors. For example, ensuring the tank sits parallel to the floor surface should increase its lifespan. A sturdy and stable aquarium stand and stable water temperatures can also promote glass fish tank longevity.

Unlike acrylic tanks, glass aquariums are UV-resistant and will not discolor over time. While they can still scratch, they are far less likely to get defaced than acrylic tanks. Of course, glass quality and sealant type are also major considerations.

We must also emphasize glass and sealant quality as two crucial factors in glass fish tank longevity. For one thing, the tank must be properly sealed with premium silicone. For another, the glass must be made from high-quality material.

Pros & cons


  • Generally cheaper than acrylic
  • More scratch-resistant than acrylic, perfect for households with kids and pets
  • Unmatched zero-fade, UV-resistant, crystal clarity for stunning views of the aquascape
  • Ten times heavier than acrylic
  • Limited shapes
  • Poor impact resistance

Acrylic Vs. Glass Fish Tanks: Which Lasts Longer?


No matter if you’re comparing 20 gallon long acrylic aquariums or bigger against their glass counterparts, glass tanks will emerge the victor when it comes to longevity. This is because they’re less likely to scratch and discolor.

However, care is necessary to maintain glass tanks’ longevity. Otherwise, you can see a glass fish tank breaking quicker than an acrylic unit because it is less impact-resistant. One stray arm swing might knock off the glass tank from its stand, crashing to the floor.

Meanwhile, although acrylic tanks don’t easily break, the fact that they’re easily defaced means that it doesn’t take long for them to become too cloudy to see. Once this happens, you’ll usually have no choice but to get a replacement.

Leaks in Fish Tank


Fish tank leaking is a common issue. After all, aquariums consist of several acrylic or glass panels joined together only by silicone (either by butt bonding or bead bonding).

The sealant might be defective right from construction, allowing water to seep through the panel joints. It is also possible that the sealant deteriorates over time, pulling away from the panel surface with the weight of the water pushing it outward.

Imagine a 50-gallon tank weighing about 600 pounds. That is 600 pounds of force pushing on the panels outward, prying the sealant from the surface. Meanwhile, it should not be an issue for a 10 gallon aquarium with a heft of only 111 pounds.

Glass fish tanks are also more susceptible to cracking or breaking than acrylic versions. Kids playing with stuff can hit the glass with a hard or sharp object, and this could be enough to create microscopic cracks that result in leaks.

To avoid leaks, you can observe the following.

  • Ensure the fish tank’s bottom is parallel to the floor surface.
  • Check the aquarium panels regularly for signs of cracks, especially the silicone sealant.
  • Do not buy second-hand or used fish tanks because they might have microscopic cracks.

Causes and How to Fix Leaks in Fish Tanks


Although there’s no definitive answer as to how long before fish tank leaks, we can pinpoint several potential causes and offer proven fixes.

  • Loss of aquarium structural integrity

A tiny crack in fish tank units might be impossible to see without illumination or magnification. Constant water exposure can lead to glass or acrylic deterioration, causing micro-cracks to form. Inspecting the cracks is crucial to determine if sealing it will fix the problem.

  • Faulty sealant

Even industrial-grade sealants deteriorate over time, allowing water to leak. We advise aquarists to drain the aquarium, remove the old sealant, and apply a new one. On average, a high-quality silicone seal should last 10 years, so make sure you re-apply the sealant before this time.

  • Problems with the aquarium stand

The best fish tank stand should support the aquarium’s weight. Otherwise, the stand might break and cause the aquarium to leak water. The only remedy for this is to replace the aquarium stand with something sturdier.

  • Aquarium filter issues

Fish tank filters require proper sealing to prevent spills. The leak you see may come from a failing filter. Replacing this component should solve the problem.

  • Leaky hose connections

Faulty tubing or hose connections can develop high-pressure areas on the aquarium, cracking the glass. Replacing the hose seals with new ones should help address the leaky issue.

Tips to Make Fish Tank Last Longer



Fish tanks can last decades with the proper care. Periodic and frequent tank maintenance ensures your aquarium will outlive others. Here are some extra tips to improve your fish tank’s longevity.

  • Buy a fish tank only from reputable sellers.

Reputable aquarium sellers offer warranties for their products. They might not have cheap fish tanks, but you will be glad about the savings in the long run from not having to buy another fish tank because the old one is beyond repair.

  • Place the aquarium in a “safe” area.

We recommend avoiding high-traffic areas for your aquarium to minimize (if not eliminate) accidents. People and objects can bump into the fish tank and undermine its structural integrity.

  • Use aquarium-safe products when cleaning.

Avoid corrosive substances and alcohol-based solutions when cleaning the aquarium. These chemicals might degrade the silicone seal and make the fish tank leak.

  • Always hire a professional to address fish tank structural issues.

Although you can fix structural issues yourself, we do not recommend it. You might worsen the situation and cause more costly problems. However, you can fix fish tank leak if it is minor, such as a faulty silicone seal.

Frequently Asked Questions


When should I replace my fish tank?

The only time replacement is a must is when you can no longer fix the broken panels or apply fresh aquarium silicone to seal the leaks. Most aquarists use their fish tanks for decades without replacing them, only periodic maintenance and timely repairs.

That said, if the tanks discolor heavily or have too many deep scratches, you’ll find it hard to look into the aquarium. If it’s not possible to make the tank transparent again, you might want to consider getting a replacement as well.

Do fish tanks leak over time?

Yes, fish tanks leak over time. After all, aquarium seals are not impervious to the effects of water pH fluctuations or normal wear. Sealants might become too dry, brittle, and crack because of prevailing environmental conditions. Or, there could be a flaw in the seal itself.

How often should you reseal your fish tank?

The frequency of resealing a fish tank depends on the quality of the silicone seal. For example, high-quality sealants can last at least a decade, making resealing frequency once every ten years.


How long do fish tanks last? If you observe proper aquarium care and maintenance, your acrylic fish tank should last 15 years. On the other hand, a glass unit can continue showcasing a dreamy aquascape for two decades.

Regardless of type, aquarium leaks are an issue all aquarists must be ready for. Spotting micro leaks is crucial so you can fix them immediately before they become bigger problems and undermine the fish tank’s longevity.

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