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Last update: April 7, 2021

Glass Vs Acrylic: Which Aquarium Is Best For You?

Acrylic vs glass aquarium compared

During my 30 years of fishkeeping, this is a question I am asked a lot:

Which is better, a glass or acrylic fish tank?

I can understand why this question comes up so often…

Both glass and acrylic, a clear plastic, are commonly used in fish tanks. At first glance, there is not much difference between the two – both are clear and capable of holding large amounts of water.

It’s not until you actually own each type of aquarium that the differences become obvious.

Over the years, I have owned many different aquariums. Some were glass while others were acrylic.

While I prefer glass, I won’t argue that there are certain circumstances where acrylic is better – I’ll get to that in just a moment.

So read on to discover the pros and cons of acrylic and glass and find out which is right for you.

But first, for those of you who do not want to get bogged down in the technical details…

If you are new to the hobby and just want a quick recommendation on which is best for you – glass is the way to go.

I recommend glass aquariums for beginners who want a tank less than 150 gallons (568 liters).

And the reason for this is simple…

As I covered in my beginner’s guide to choosing a fish tank – incredible care must be taken with acrylic tanks to avoid scratching, especially during cleaning.

It’s hard to appreciate how good your fish look when you are staring through a scratched tank.

Not to mention that glass aquariums are easier on your wallet!

These two points make glass aquariums more suitable to beginners than acrylic ones.

That said, acrylic does have its benefits, namely being lighter, which makes it more suitable for large tanks – tanks so big that most beginners wouldn’t even consider them.

The difference between glass and acrylic aquariums

As you see in the table below, glass and acrylic are very different materials, each with advantages and disadvantages.

Don’t worry if this table doesn’t mean much to you, I will cover each point in greater detail later in the guide.

Quality Glass Acrylic
Cost Cheap Expensive
Scratching Resistant Scratches easily
Weight Heavy Light
Shapes Limited Varied
Impact resistance Poor Good
Clarity Constant Yellows with age

Now that you have read the summary, let’s take a closer look at the differences between glass and acrylic aquariums.

Cost

Winner: Glass

This one always comes as a surprise, but glass aquariums are usually cheaper than acrylic.

I know, I know…. Acrylic as a material is cheaper to manufacture and transport than glass. But a complete glass aquarium is still cheaper than an acrylic one.

And the reason for this is simple…

Glass aquariums are more popular.

Because of this, more glass aquariums are manufactured, which reduces the total cost.

However, there is a tipping point when acrylic aquariums become cheaper than glass aquariums. If you are shopping for a particularly large aquarium, around 150 gallons (568 liters) or larger, an acrylic aquarium is cheaper.

This is because glass weighs more than acrylic and is cheaper to transport.[1]

And that brings me to my next point…

Scratching

Winner: Glass

This is the main reason why I recommend glass, especially to beginners. Acrylic scratches waaaaaaay too easily.

My last acrylic aquarium was actually scratched during transport. Despite all the protective packaging, when I unboxed my new aquarium, it had a noticeable scratch down the left side.

But let’s say that your acrylic aquarium arrives safe and scratch-free. Anything brushing against the tank can scratch it. Yep, even just walking by your tank and making slight contact can rough up the surface.

If you have young children that constantly touch or play near your tank, or even a curious cat, steer clear of acrylic.

Even critters living inside your tank can scratch the surface. The sharp shell from a snail or sharp tooth from a fish is all it takes.

And when cleaning, you need to use an acrylic-safe algae scrubber. And good luck if you accidentally get a small piece of gravel or sand caught in it – it’s a one-way ticket to scratch city.

There are acrylic polishing kits that can be used to restore acrylic tanks to their former glory, removing all signs of scratches. But do you really need more chores? And besides, you will have to drain your aquarium to remove any scratches from the inside.

Glass, on the hand, is much more difficult to scratch, that’s why it makes such a great material for the windows in your home – it is difficult to accidentally scratch glass!

Acrylic aquariums look “beat up” much quicker than glass aquariums.

Weight

Winner: Acrylic

I don’t need to tell you that glass is heavier than acrylic. But just how much heavier glass is may surprise you.

Imagine you have two aquariums that are the exact same size. The only difference between the two is that one is made from acrylic and the other from glass.

The glass aquarium can be as much as 10 times as heavy as the acrylic aquarium.

The lighter weight of acrylic has advantages.

A small acrylic aquarium is much easier to lift than a glass one. You can easily move the tank around your home, even with water inside.

And when it comes to large custom-made tanks, you will need to consider the amount of weight that the floor in your home can support. Choosing acrylic over glass is a commonly used method of reducing the overall weight of the tank.

Shapes

Winner: Acrylic

The hard, brittle nature of glass makes it difficult to shape. This is why most glass fish tanks are square or rectangular.

Curved glass aquariums have the added problem that it “bends light,” which makes the fish on the inside appear larger or smaller than they actually are.

Acrylic, on the other hand, is easily molded into any shape that you can imagine. It also bends light less, which means that your fish look how they should.

Impact resistance

Winner: Acrylic

Okay, so this one is only relevant in the event of an accident. I don’t need to tell you to prevent heavy objects from crashing into your aquarium!

Acrylic is much more resistant to impacts than glass, which can break or chip.

But if bumps and crashes are a concern, you are better off choosing a different location for your fish tank.

Clarity

Winner: Glass

The glass windows in your home are designed to let light in.

But this light can damage acrylic, causing it to become yellow and brittle over time.

UV light to be specific. If sunlight hits your aquarium (it shouldn’t) or if you have UV aquarium lights to help with plant growth – it will eventually wear down the acrylic.

While there are “UV-resistant” acrylic aquariums, even these eventually discolor.

Every acrylic aquarium I have ever owned has reached the stage where it becomes cloudy. And while the process may have taken years, it seems like it is unavoidable.

Glass, on the other hand, does not suffer from the same problem and will remain clear, no matter how much light shines through.

Workability

Winner: Acrylic

If you love DIY projects and want an aquarium that is easily modifiable, acrylic is the way to go.

You can easily drill holes in acrylic to make way for pump outlets, overflows or anything else your creative mind can think up.

While you can still drill through glass, as long as it isn’t tempered, it is a nerve-racking experience and requires much more care than drilling into an acrylic tank.

Conclusion

As you see, the pros and cons of each material heavily impacts how you can use your aquarium.

If you want an unusual-shaped aquarium or plan on modifying your tank with a drill, acrylic is the way to go.

But again, for the vast majority of you, it’s hard to beat a good glass aquarium. With proper care, a glass aquarium will outlast you!

What type of aquarium do you prefer? Let me know in the comments below

Ian Sterling

I've been keeping fish for over 30 years and currently have 4 different aquariums – it's an addiction. I'm here to teach you everything there is to know about fishkeeping.

I also use this site as an excuse to spend lots of money on testing and reviewing different aquarium products! You can find my reviews here.

Comments (47)

Dear Mr Ian, your post is extremely comprehensive and helpful. I have been a fishkeeper for 11 years now and still there are so many things I have just learned thanks to you.

Hi Corinne,

Thanks for the feedback. I think that is the most exciting part about this hobby, there is always something new to learn!

I rescued a Beta fish from my office and just purchased a beautiful glass tank for it. I was told that a glass tank dirties faster and becomes cloudy with algae as with the acrylic I wouldn’t have that problem. Is this true?

Hi Úrsula,

This is incorrect. Making sure your tank is cycled (cycle your tank before adding your fish), your water parameters are correct (Use an aquarium test kit) and regularly performing water changes and maintaining your tank will have the greatest impact on algae and cloudiness.

It doesn’t matter whether you choose glass or acrylic here.

I also appreciate your post and information! Long story short, my son, 11, currently has a 10 gallon tank, and a small one (with a wall) for his two beta males. For Christmas his number one wish list item is a 50 gallon tank so he can get koi fish. He found an acrylic tank online, oddly cheaper than glass, and I needed help choosing. Definitely beginners! We have three dogs and kids over so acrylic is sure to be scratched from what you said. Thank you!!

Hi Karen,

That sounds like an amazing Christmas present! Your son is very lucky.

If you are located in america, as I type this, Petco is having their dollar per gallon sale. Aqueon tanks up to 29 gallons. Tanks up to 75 are 50% off. You could grab a deal on a glass aquarium here. You may find it’s comparable to the acrylic tank your son found. This deal is only available in store – not online. It ends 11/17

Just be mindful that it’s generally recommended you only stock 1 inch of koi per 10 gallons of water while they are growing – so if a single koi is 5 inches long, you would need a 50 gallon tank for that one fish.

Hi Ian,

Great tips and I’ll get to Petco this week!!

Sounds like his desire to get two koi will have to wait. I’m willing to do 75 gallons, (especially now that I know about the sale!), but that wouldn’t even be enough for two. I’m just a little worried about the weight with glass and water since his bedroom is upstairs. I’m not sure where I would check weight capacity for our house.

If he got one koi, would he be able to also get other fish? He currently has a black moor goldfish that will be about 10”, a black molly and a tetra. He’d of course like to get more, hence the bigger tank. He loves catfish but we must be doing something wrong because we lost all three.

I know that I’m veering off the glass vs acrylic topic but I’m struggling to find good resources and you’re clearly very knowledgeable about tanks and fish!!

Hi Karen,

Just a heads up, apparently not every state (such as Hawaii) is doing the sale, so ring ahead.

A 75 gallon tank filled with water would weigh around 850 or so pounds. I cannot say whether your house is up to code and correctly built. But generally speaking, you would expect 4 adult males to be able to stand in the one spot without your floor collapsing, right? Well, that’s a similar weight to a 75 gallon. Drop down to 50 gallons and it’s closer to 600 pounds.

There is a reason Koi are generally kept in ponds, they need a good amount of water. While a 50 gallon might hold a small koi for a while, it doesn’t take into account that the Koi will grow (up to 15 or so inches for aquarium suitable species.) A young Koi can grow 4 inches in a year. So a tank that is suitable now likely won’t be suitable in the near future. Given this, I’d be hesitant to recommend koi for this tank. I know it’s not what you want to hear, but any fishkeeper who will tell you otherwise is likely trying to sell you something and doesn’t have the wellbeing of the fish in mind.

Hi Ian,

You gave me the idea to check with our code inspector. Thank you!

This will be a big bummer for my son. And I know that I’ll hear “but my friend has his in a container and they’re fine.” (It’s a large plastic tote.) The plan for both kids was to build something outside next summer. However, we live in upstate NY so they’d need to come inside for the winter and need adequate space. With that said, he’ll ultimately care about their well being. There are plenty of fun and interesting fish and a larger tank will still allow him more variety.

Once again, thank you for your honesty and tips! Also for the reviews on various products. Extremely helpful as we begin this journey!!!

I’m glad I could help. There are so many amazing fish that can happily call a 50-75 gallon tank home that I’m sure your son will find another species that will excite him just as much as Koi.

All the best 🙂

Hi sir,
one thing i wanted to know about “acrylic tank” is my local aquarium shop guy told that acrylic is not good for fishes and its made of some chemicals so that fishes will die is it true or false.

Hi Mohan,

Properly sourced acrylic from a reliable manufacture shouldn’t leach anything into the aquarium at normal temperature.

Hi Ian,

I am planning to buy a fish tank, I would like to keep a total of 9 fishes, 4(gold), 4(small koi ) 1 silver shark.
What tank size would be better for me.

Hi Praveen.

A pond. These fish have a very large bioload and the koi grow quick. They would quickly die in all but the largest of tanks. Check out aqadvisor for fish you can stock in smaller tanks.

Hello Ian,
Is there a significant failure rate difference between glass and acrylic? Cory, at Aquarium Coop did a video on a blow-out of his 350 gallon glass tank; the damage was extensive. Also, if there is a difference, does it make sense to mitigate with heavy frames to limit flexing? Thanks

Hi James,

I can’t comment on the failure rate as I have not tested one against the other in a controlled environment. Anecdotally, I hear more stories of glass aquariums breaking but this is likely due to it being the most common material used in aquariums. I am unaware of Cory’s exact circumstances and what lead to the breakage, but I have seen plenty of 300+ glass tanks that have been going strong for many years without issues. My local aquarium has a 350 gallon display tank and they have not done anything out of the ordinary to brace it.

I like glass but from time to time acrylic is much more versatile with the shapes that can be produced. The price has always deterred me from buying them but in an area prown to earth shaking I heard there better but still again I used glass in these areas. The cost of a proper set up for a new aquarium is high depending on what is put in it so a price deal on the glass and stand is very welcome as I have experienced the money saved will be enough to buy most the other necessaties for the tank. This formula worked well with 125 gallon tank. I’ve been keeping fish and turtles for 40 plus years

Hi Alan,

Thanks for sharing your thoughts. You make an excellent point on saving money, which subsidizes the cost of all your other equipment!

Either I’m misunderstanding or your wrong, acrylic as a material is not cheaper than glass. Glass aquariums are cheaper partially because the glass itself is cheaper

Hi David,

Perhaps I could have worded this better, but the cost in this article takes the whole supply chain into account, not just the cost of producing the material.

Hi Ian! If you recall, some time back we upgraded Gup’s tank to a bigger one. Honestly though, if I’d had my way and we’d been able to find one, I’d have gotten them an acrylic tank, like their previous one, and not this glass tank.

One of the reasons why is what I wanted to ask you about now — I’m frustrated to find myself having to deal with this icky scum that keeps forming on the silicone that lines the “seams”, something we never had to deal with before in the acrylic tanks, which are all of one piece (so this is not an issue in Betta’s tank at all). This scum is sort of orangey.. diatoms maybe?.. and come off easily with a toothbrush, but then bits of it start floating about in the water and we have to scramble to get rid of *that* next. For whatever reason, it’s primarily on those silicone seams.

What is it/why is it there? And more importantly, what’s the best way to deal with this/get rid of it/clean it off? It doesn’t seem to be affecting the fish health-wise thankfully!!

Hi again catherine,

I hope Gup is doing well. Overtime clear silicone will brown and gunk up. It’s normal and if your tank parameters are okay then it’s nothing to worry about. In fact, when many people seal their own tank, they choose a black silicone for this very reason, it doesn’t stain and hides this unsightly scum.

Wipe away whatever you can with a cloth. Don’t use a razor blade near silicone. It’s likely some of it will have worked it’s way underneath the edges of the silicone. Don’t worry, this is fine and while it may be unsightly, shouldn’t pose a risk to gup.

I’m looking forward to getting back into having an aquarium at home. I want to build one that would be greater than 500gal. for Chiclid.
I was wondering, could I build one in acrylic and glue/laminate a thin pane of glass over it so I would get the best of both world? No scratching and easy to clean while keeping cost and weight down?

Hi Yves,

I have no experience with combining the two materials. I think the biggest issue would be what happens between the glass and acrylic. You can’t clean between the two and whatever glue you use may not be perfectly transparent. You would have to do more research here, but I think it’s likely there is a reason why I have not seen one of these in 30 years of fish keeping – the drawbacks are likely too large.

wow as 4 a 500 gallon, you could look into getting stingrays and arowanas instead of cichlids cuz if I were you, getting arowanas is a one in a lifetime chance and they require large tanks the size of 250-300 gallons or larger and same goes for stingrays. as for cichlids, I find them attractive and colorful and I have a cichlid tank but only 80-gallon and it would be a waste as cichlids I would say a 100-200 gallon.

But its your tank so its your choice and if you do get cichlids, try oscars

You forgot about one major point.
Glass has an eventual 100% failure rate. Acrylic does not.

Eventually, the silicon seams on a glass tank will fail causing a leak. Usually we catch it but if you don’t, massive damage to your floor and loss of fish is at risk, especially if you breach while away for the day.

Hi Fish Tank,

You make a excellent point, but the same could be argued that on a long enough time line, even acrylic has a 100% failure rate. Every thing ages – my wrinkly face is proof of that 🙂 By the time the silicone seals give in 10-15 years, acrylic has long since become scratched and aged. I have found that it is looks obvious when silicone needs replacing and if you are performing a weekly tank maintenance with an exception, it’s hard to miss. Thanks for adding to the article!

Hello. I am infant with it all. I’ve bought 5 gal acrylic. Nothing up & running yet, still gathering supplies. My 1st main worry is gravel scratching bottom? Will it cause bacterial issues to hurt my fish? I’m considering using a breeding mesh net to bundle wrap gravel in (tie gravel inside like bagging it) to reduce scratching as well as easily lift gravel out for thorough cleanings, but 24/7 mesh net concerns me with potential bacterial growth also? I plan for my rookie days, only one betta and eventually adding one blue velvet shrimp so tank wont be over populated, but betta aggression concerns me for shrimp especially adding after betta claims territory all his very own. So not certain with the little housekeeper shrimp yet? I just want tank safe, no bacteria hazards & I have seen hints of visible mesh netting in tank bottoms before but really want your advice. I plan to get betta in another month give or take. I’ve read your advice to others but didnt see anything like this so I will be grateful for your advice. My heart breaks for some of these creatures in pet stores, little cups, etc. Mine will be king of his castle. I want the best I can give and you are that, so thank you in advance for any and all advice.

Hi Jimi,

Glass is preferable in my opinion, but if you are performing proper maintenance (cleaning, water testing) and you properly cycle your tank, then you won’t have issues with whatever you choose, even with scratches on the bottom.

If you include a shrimp with your betta, give him somewhere to hide, fine plants that a betta won’t be able to get to him work best, if you plan on adding the two together.

It sounds like you will give your betta an awesome home. Don’t forget to read up on cycling before you buy your betta!

Greetings, I’m a first time Fishtank- Owner and I’m looking at a glass 96 inch long by 24 inch wide by 36 inch tank. The tank will serve as a room divider being clear on both sides. I would like to purchase the tank but I’m not certain where I should put overflow holes. People say that glass is really heavy but my contractor said that he can build a custom and wall stand to support it and then build the wall and in around it to access the hood and equipment underneath. Is it unrealistic to have a glass tank of this size in the application that I am looking to use it for?

Hi Monica,

That’s about a 350 gallon tank and is certainly on the large side. However, I have seen similar sized tanks used in walls (they look stunning) the actual logistics of this are beyond me and you would need to speak to someone with experience supporting a tank of this size – with water alone, the tank will weight close to 2,900 lbs. Once you add your substrate and decorations this will be considerably heavier.

Good Evening Sir,

I am going to build aquarium….in my city (India).I need suggestion who will build this type of work….and need some guide on fish keeping to maintain it…

Hi Kuldeep,

Unfortunately, I am based in the United States, I do not know any manufacturers in India.

Hi Ian,

I’m planning to own a large cylinder fish tank (around 430 gallons.) After carefully reading your article about the differences, I am sure I’m going with an acrylic tank. Although I find the glass tank pros fit my needs more (especially scratching and clarity.) May I ask you, if I’m to go with any of those materials, what’s your recommendation on its thickness?

Thank you

Hi my son is 20, he started with a 10 gallon, then 20 ,gallon which he still uses and has a 30 gallon. He does real good taking care of them, water always clear so i thought i would surprise him with a bigger one bit i know nothing aboutcthis and can not ask him it will spoil the surprise. Im a single mom and can not spend 409 or higher. Can you advise me in a goix brand and size fir the money. Thank you in advance

Hi Silvia,

Depending on how big you want to go, it may be best to contact your local aquarium builder. A large part of the cost of the product is shipping (tanks are both heavy and bulky) and having them made locally by an expert can really get the cost down. If you can pick it up yourself, you’ll likely save on shipping. Google “aquarium builder” and see whats around you.

I’ve bought a 150 gallon 72x18x24 aquarium about 12 years ago. (Glass) Took very good car of it. Just recently the center brace cracked and separated at the front glass. I had to drain the tank a quarter way down to relieve the bowing of the glass.

2 questions..

1 is this common and can it be avoided.

2 where do I find a 150 glass aquarium these days. I’m not finding anything in my area and nobody wants to ship glass.

Hi Michael,

1. A glass tank lasting 12 years is commendable. It’s about this time that one should look into resealing an aquarium. On the brace issue, I don’t think it’s particularly common.

2. Where are you located? I can only speak for some US states where I have lived, but finding a 150g shouldn’t be too difficult.

Hi Mr. Ian,
Greetings of the day

I’m from India. Into this hobby for some 9-10 years, started with a tiny aquarium in a whisky bottle to keep it a secret, then moved on to 5 gallon tank, then to 30 gallon tank (both of which i still have with blood parrot fishes and dimple bars).
Planning to build up a community 125 gallon tank in wall, preferably with glass.
Please suggest me which type of fishes should i keep and in how many numbers each.

Hi Anirduh,

Unfortunately, I don’t know what is available in India, your water quality and similar. You should speak to your local fish store, they will be in a better position to help you!

Thanks for the very useful information
Apart from aquariums, I have an outdoor swimming pool and I was considering of making a top sliding cover from acrylic. I want to enjoy the pool view even when it is coverd that’s why I though of the acrylic. Do you think that’s a good idea ? By the way the temperature in my area can be as high as 45 C so after reading your article I understood thay this might affect its clarity!?
Please advise

Hi Amnj,

Unfortunately, my experience does not extend to alternate uses – My experience relates to aquariums.

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