Best 40 Gallon Aquarium & Buyers Guide

Aquariums come in all shapes and sizes so it may be difficult navigating the murky waters of the aquarium market to find a suitable tank for your next setup. 40-gallon aquariums offer a medium tank that is versatile and able to fit in quite confined areas.

Common uses of 40-gallon tanks include breeding and small reef setups with plenty of kits available on the market for beginners which include many of the essential accessories an aquarist may need or even stands and custom hoods. With so many choices available for when you’re looking to purchase a new aquarium, below is a brief overview and review for nine popular, common 40-gallon aquariums listed on MyAquarium so that you can make an informed, knowledgeable decision on your next tank.

Cheap & Good

Our Favorite

Customers Choice

Clear-for-Life 40 Gallon Uniquarium Fish Tank

Coralife LED Biocube Aquarium LED

SeaClear 40 Gallon Acrylic Aquarium


36 x 15 x 16 inches

20.25 x 21.88 x 21.5 inches

36 x 15 x 16 inches


40 gallons

32 gallons

40 gallons



55.9 lbs

20 lbs






Sapphire Blue



Our Rating

Here is our List of the best 40-Gallon Aquariums (Tanks) on the Market today:

1st Coralife LED Biocube Aquarium LED

This is an amazing kit manufactured by Coralife – a 40-gallon fish tank made out of glass – it comes with everything you need. Its top feature is customizable and programmable lighting.

The kit can be used for fresh and saltwater setups as long as your aquarium won’t require intense lighting as the lights it comes with are not good enough for densely planted tanks.

It has a very pleasant design, top quality materials and impressive lighting options that will be a delight to watch. It has an integrated 24-hour timer and you can set sunrise/sunset as well as moonrise/moonset times replicating the natural day cycle in your aquarium. It’s very pleasant to have a dimly blue-lighted aquarium at night – I just love it when I walk past mine and it has that blue glow – sometimes I just sit and watch the fish at night too – gives your fish tank a lot more life! Some fish even glow nicely under it, like my yellow Danio (Zebrafish).

It comes with a quiet, adjustable filtration system that can easily handle everything in your tank as long as you do not overpopulate it. A great option for beginners as it has everything you need and is easy to use – the downside is that it is very difficult to customize the setup so if you prefer to change filtration systems, lights, etc – you’re better off with getting something simpler.

The kit does not include a heater, so if you know that you will have issues with keeping the water temperature where you need it for your fish, you’ll need to get one yourself.

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2nd SeaClear 40 Gallon Acrylic Aquarium

The SeaClear 40-gallon aquarium is a great new offering by SeaClear that is a reasonable value for money. The 36″ wide x 15″ long x 16″ high tank is composed of acrylic material in a rectangular shape providing strength and support which cannot be shattered or chipped, unlike glass counterparts.

The tank is built with a wide variety of uses in mind suitable for the reef, marine, salt, and freshwater setups. Sea Clear products are known for their exceptional quality which is the main focal point of this particular fish tank over other similar tanks. However, the pricing of this tank is a little higher than other competing tanks such that one would need to decide whether their budget would permit a slightly more expensive spend for the extra quality on offer.

Overall though, MyAquarium believes that the price to quality ratio and included hood does match up making this quite a good choice although the lack of accessories which one might find in a starter pack does make this less appealing to the beginner aquarist. The product also comes with a limited lifetime warranty epitomizing just how seriously SeaClear views the quality of its products. This particular acrylic tank is also more suitable for a warmer ecosystem since acrylic has much higher heat retention than glass although some aquatic enthusiasts believe it discolors.

However, MyAquarium’s extensive testing along with consumer comments shows that the SeaClear product, in particular, does not discolor even after long term use quite possibly due to the quality raw materials SeaClear uses to produce their tanks. Overall, the SeaClear 40-gallon tank is a good medium-sized tank, one of the better acrylic offerings and excellent for existing aquarists who are just looking for a new, good quality tank without any accessories or extras. Find more details on the SeaClear 40 Gallon Acrylic Aquarium here.

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3rd Red Sea MAX E-Series 170 Rimless Aquarium 45 Gallons with ReefLED 90

Red Sea MAX E-Series 170 Rimless Aquarium 45 Gallons with ReefLED 90 – this is a brilliant, ultra-high quality kit from Red Sea that can satisfy any aquarist, beginners and experienced alike.

It can be set up as a freshwater tank but it is mainly built for saltwater and specifically reef tanks. The company specializes in reef tanks and they do it to perfection. This kit will get you everything you need, a very good quality tank, a cabinet that matches the tank perfectly and includes a complete water filtration system PLUS a special reef lighting system.

The tank itself is all 12mm, ultra-clear rimless glass that allows for a great viewing experience.

The cabinet includes a sump, protein skimmer, twin pumps that recirculate the tank’s volume 16 times per hour, filters and it is “chiller-ready” which means that you have room underneath the tank to add a chiller should you need to. it has an Integrated Power Center where you can easily switch all 7 electrical components on and off and it comes in both white and black.

The lighting system is amazing too, it has integrated wifi, it’s easy to set up and connects seamlessly via the provided mobile app. The app itself will allow you to set up all the parameters that your coral will need for spectacular colors.

Although the price is a bit steep, you know that you get a complete professional kit from top to bottom that’s also very appealing visually!

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4th Clear-for-Life 40 Gallon Uniquarium Fish Tank

Clear For Life also produces a 40-gallon Uniquarium made of acrylic with a built-in 3in1 filtration system. Unlike glass, acrylic doesn’t crack or chip providing a stronger more structurally sound aquarium that will handle almost anything you can throw at it. However, some aquarists say that acrylic discolors over time may be something to consider however this can be minimised by regular cleaning. The tank is a standard size for 40 gallons with dimensions of 36″ Wide x 15″ Length x 16″ High. The medium size tank is suitable for a wide variety of uses including salt and freshwater.

This particular model is one of Clear for Life’s premium products and includes filtration system making it reef ready or good a freshwater plant setup. The Clear For Life group are known for their exceptional, high-quality products and the 40-gallon Uniquarium is no exception backed by a limited lifetime warranty. This particular tank doesn’t include lighting, a hood or other accessories but the quality tank and filtration system provide excellent value for money and any extras can be purchased for quite a reasonable price separately. This makes it a great tank for experienced owners and beginners due to the high-quality nature of the product and the minimal maintenance required to run this tank smoothly.

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5th SeaClear 40 Gallon Junior Executive Aquarium Kit

Similarly, SeaClear also produces a similar-sized 40-gallon tank called the Junior Executive Aquarium. This is another high quality, premium rectangular acrylic tank similar to the Uniaquarium with a similar excellent value for money proposition. The tank is standard, rectangular with the dimensions 36″ Wide x 15″ Long x 16″ High making it suitable for even fairly small spaces as far as aquariums go. It is extremely versatile and suitable for reef, marine and freshwater setups and is a much-loved favorite of aquarium owners.

SeaClear also includes many extras with this package including a hood, fluorescent lighting, power filter, plastic plants, net, fish food and water conditioner making this the perfect beginner package. As a result, this tank is amazingly good value for money and provides everything you need to get started. Experienced aquarium owners who may have some if not all of these extra goodies already should still consider this option to the high-quality nature of the tank and great price. This means that even with the inclusions it could still be more cost-effective than purchasing a tank on its own and having a few extra plants or nets to manage your tanks is always handy.

Therefore, the SeaClear 40-gallon acrylic aquarium junior executive kit is a great, quality product that provides a more rounded package than what Uniaquarium and Sea Clear have to offer. Its reputation among aquarists and impeccable history built on quality makes the Medium Executive Aquarium a great investment for anyone looking at a new tank. If you’d like further detail on the aquarium read our complete specification and review here.

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6th Aqueon 40 Gallon Breeder Tank

Aqueon also provides a high-quality 40-gallon fish tank offering providing a medium-sized glass tank for aquarium owners. It is technically classed as a breeder rectangular tank with 36″ wide x 15″ long x 16″ high dimensions. All the glass panes aren’t tempered and are ¼ inch thick making them suitable for drilling the mounted lighting or filtration. Aqueon utilizes a black one-piece center braced frame to prevent glass bowing.

The tank is extremely versatile providing a great setup for reef, marine or freshwater environments or even as a dry tank for reptiles. It doesn’t, however, come with a hood or any accessories such as nets, filters, and lighting which would need to be purchased separately. As a result, a beginner may be more interested in a packaged tank with extras bundled in. Yet for a standard, high-quality medium-sized glass tank the Aqueon 40 gallon fish tank is extremely good value for money and would overall be great for beginners or pro aquarists alike. Find further details on MyAquarium here.

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7th Top Fin 40 Gallon Hooded Aquarium

Conversely, the Top Fin 40 Hooded Aquarium is another competing 40-gallon glass tank offering for use on a table with its lightweight and compact setup featuring dimensions of 36″ Wide x 18″ Long x 16″ High. The tank has a sleek black frame providing extensive structural support giving it a sturdy feel and includes center bracing to prevent glass bowing. Like the Aqueon tank and all the other glass tanks reviewed in this MyAquarium article, it is extremely versatile with the Top Fin 40 being suitable for freshwater, saltwater, and reptilian use. It is a standard rectangular shape with similar dimensions to other 40 gallon tanks and the glass is of high quality. However, with all glass tanks, there is a risk of cracking over time thus acrylic tanks are generally more durable yet have their own downfalls as well.

The Top Fin 40-gallon fish tank is quite good value with a reasonable price point for beginners or professionals looking for a new tank. It does come with a black-trimmed hood as standard with a fitting for a fluorescent light sold separately. Other accessories such as filters and nets also need to be purchased separately which detract slightly from the value add although this would mainly affect new aquarists.

Overall, even if one was to purchase all the required accessories separately, the total outlay would still be less than some of the more overpriced tanks on the market. In order for use with reptiles, the fluorescent light fitting could still be used simply by placing a UV light in the fitting instead, making it convenient for use in both niches. The Top Fin 40 is a sturdy, well-built glass tank that won’t disappoint anyone looking for a good aquarium deal. For more detail on this Top Fin aquarium read our review here.

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8th Aqueon / All Glass 10037 37 Gallon Aquarium


Aqueon also offers another medium-sized tank in this range, the 37-gallon All Glass / Aqueon 10037 rectangular aquarium. This is slightly smaller in capacity than 40-gallon offerings but still fits the size category and is another alternative option for those looking for approximately 40 gallon sized tanks. It is made of glass, with the slightly different dimensions of 30.3″ Wide x 12.5″ Long x 22.8″ High and is extremely versatile for marine, freshwater or reptilian use.

The simple Aqueon 37 Gallon fish tank design comes with a modern black or oak trim creating an extremely sturdy product although with any glass tank the potential of cracking and chipping remains. The frames are once piece with central bracing to prevent cracking and bowing, providing and overall lifespan increase however a lifetime warranty is not included. The tank is extremely reasonably priced, providing great value for those on a budget or just looking for a cheap tank to quickly increase the capacity of an existing setup. No accessories are included in with this aquarium either including hood making it less attractive to beginners however these can be purchased separately at a minor expense.

Overall MyAquarium believes is a great budget tank with a wide variety of uses that would suit any aquatic fanatic however there are also many other good options in a competitive marketplace. Read our in-depth review of the All Glass 10037 Aquarium here.

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Aquariums come in all shapes and sizes with different price points, inclusions, and uses. Above are just some of the medium-sized fish tanks available and the advantages and disadvantages which come with each piece. Every fish tank is different, from breeding tanks to reef aquariums and small household tanks which maximize the viewing experience. Choosing a 40-gallon aquarium can be difficult however with the information at MyAquarium we hope to make that process just a little easier with our vast knowledge across a wide variety of tanks and setups. If you are looking for larger aquariums, need a setup guide or extra information on maintaining and running an aquarium, look through for more helpful content.

If you are in the market for larger 55 and 75-gallon tanks, we have similar guides at which can be found at the links below:


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