40 Gallon Breeder Tank (The Dimensions & Setup)

40 gallon breeder tank

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Whether you are a pet owner or a breeder, housing your fish in the right kind of tank is vital. 

Sometimes, you may make this choice depending on the species of fish you want to bring home. So, while aggressive breeds such as cichlids will require a gigantic 100 Gallon tank, schools of small catfish will be just as comfortable in smaller 30 Gallon tanks. 

And it’s not just about the fish; aquarists and breeders may prefer certain types of tanks that make handling and aquascaping easier. Similarly, a 40 gallon breeder tank offers perks that make it worth considering. 

40 Gallon Breeder Tank Dimensions

Tank SizeL x W x HEmpty WeightFilled Weight
40 Gallon Long48″ x 12″ x 16″55 lbs455 lbs
40 gallon Breeder36″ x 18″ x 16″58 lbs458 lbs

A standard 40-gallon breeder tank measures 36-3/16″ x 18-1/4″ x 16-15/16″. It is also worth noting that an average tank of this size weighs 58 lbs. when empty, so it will weigh about 458 lbs. when full. 

However, the weight also depends on the material of the tank. For instance, an acrylic tank may weigh about 20 to 25 lbs. more than a glass tank. 

And although it holds the same amount of water as a regular 40-gallon tank, the breeder model is much shorter. For a better idea, consider how regular long tanks with the same holding capacity measure 48-1/4” x 12-3/4” x 16-7/8”. That said, in addition to the significant height difference, breeder tanks provide a greater surface area.

Why Would You Want A 40 Gallon Breeder Tank?

Good Size

What separates a breeder tank from a regular tank is the ease of handling fish. Considering how fish are agile and slippery, the lower profile of this tank allows breeders to catch the fish easily when the need arises. 

At the same time, regular fishkeepers and pet owners may also prefer 40-gallon breeder aquariums if it is more suitable for their fish. For instance, some species, such as the lungfish and guppies, may be more comfortable with breeder-type tanks as they do not have to swim far to breathe in atmospheric air. 

Perhaps owners may keep amphibians or reptiles that enjoy swimming around but also need to come up to the surface from time to time. These include musk turtles, which are considered bad swimmers and get quickly tired in tanks with a greater height. 


40-gallon breeder tanks are affordable — especially if you know where to look. 

That said, most big pet supply chains in the US have frequent discounts, during which you can get them at about half the original price. Moreover, you may ask about the upcoming Petco Dollar Per Gallon Sales to get these for a flat rate of $40. 

Better Design

As the name suggests, the low profile of these tanks makes them well-suited for breeders who need to handle the fish from time to time. On the other hand, breeder tanks boast a wide surface area, which has made them popular among aquascapers. 

That said, breeder tanks offer much more space to build layers and add aquarium decor, such as rocks, driftwood, plants, and so on. In fact, the low profile makes it a suitable option for plants and reefs, as light can easily reach the bottom of the tank. 

Unsurprisingly, 40-gallon breeder tanks are more popular among reef keepers than their 50-gallon counterparts, even though the latter has a greater holding capacity. And aside from the low height that allows light to reach the reefs or vegetation, many suppliers sell braceless tanks that do not block out natural light. 

What’s more, these may be made of thin glass, which cuts down the costs and weight to make it easier to handle. Not to mention how the sharp and clean look of braceless glass tanks, combined with healthy and mesmerizing reefs, can elevate the design factor of your home. 

40 Breeder Tank Setting Up

Buy a 40 Gallon Breeder Aquarium

First off, you need to choose a 40-gallon tank that suits your requirements. For instance, you may select an acrylic tank or a glass tank, braceless or cross brace, and so on. 

If in doubt, consider the Standard 40-Gallon Breeder Tank from Aqueon or SeaClear Acrylic Aquarium Combo Set from Amazon, which are excellent options for those looking for a high-quality and affordable tank. That said, this product is equipped with clean silicone edges and durable glass construction that can endure most types of applications. 

And whether you wish to bring home saltwater or freshwater fish, this tank will fit the bill. Moreover, the glass aquarium allows light to enter the tank from all sides, making it a suitable choice for reef keepers. 

SeaClear 40 gal Acrylic Aquarium Combo Set, 36 by...
  • Combo includes aquarium, reflector and electrical 24" light fixture
  • Acrylic aquariums are clearer than glass, 17 times stronger, and only half the weight!
  • More impact resistant and less prone to chipping or cracking than glass, making it safer around children...
  • Safe for Salt or Freshwater
  • You won't believe how your fish and decorations will pop when viewing this beautiful SeaClear aquarium

Filter for a 40 Gallon Breeder Tank

Next, a suitable filtration system is required to keep your tank parameters in check and maintain optimal water conditions. For this, you may opt for the Ecco Pro External Canister Filter from Eheim, which is available in three sizes for aquariums up to 80 gallons.

This well-reviewed product uses a pre-filter and multi-stage filtration design for optimal performance. At the same time, the device is easy to set up and maintain, with long intervals of three to six months between cleanings.

To prime it, all you need to do is flip the handle, wait for the water to fill up, and then flip it back. Once you plug it in, your work is done. Moreover, you can put the filter out on display or hide it behind a cabinet. Either way, you can rely on this efficient device to quietly carry out its functions. 

CO2 Regulator

A CO2 regulator helps maintain the carbon dioxide levels in a tank. This is especially vital for aquatic vegetation, which will turn yellow and eventually die if there is not enough CO2 to go around. 

While there are plenty of options on the market, you can add a bit more style to your aquarium set up with the Premium AQUATEK CO2 Regulator. Donning an industrial-style design, this device is made of high-quality brass that guarantees durability and dependability. 

That said, you can rely on this CO2 regulator to enrich your tank with as much as two to three times the natural concentration of carbon dioxide in the air. At the same time, it is equipped with dual gauges and a needle valve so you can maintain the desired levels of CO2 to support plant growth. 

What’s more, you can use this multipurpose device in the greenhouse, in addition to the aquarium. 


Apart from the filtration system and a CO2 regulator, a heating device will be necessary to keep the tank water at comfortable temperatures for the fish and vegetation. 

For a 40-gallon breeder tank and an aquarium with a holding capacity of 55 gallons, the Pro Series Aquarium Heater from Aqueon provides an excellent option. However, bear in mind that this heater has an adjustable heat setting only between 68 to 88 degrees Fahrenheit. 

Once you set the temperature, you can fully immerse the device in the tank and place it anywhere around the tank with suction cups. And don’t worry about it overheating; the heater comes with an auto shut-off feature that helps it cool down instantly. 


Proper lighting provides necessary oxygen to your fish and also supports photosynthesis in aquatic plants. At the same time, a well-lit aquarium raises the aesthetic appeal of your set-up while providing illumination to the room. 

For a minimalist lighting product to put in your aquarium, consider the FugeRay Planted+ Aquarium LED Light Plus Moonlights from Finnex. Despite its sleek design, this LED fixture can light up an entire aquarium. And while it is equipped with red LEDs to support aquatic life, you can switch the light settings to a calming moonlight tone once the sun goes down. 


Many aquarists use a dirt substrate for their aquariums as these are easily accessible. However, dirt can be messy and cause scratches on your aquarium glass. An affordable alternative would be the Black Diamond Sand, a blasting grit “sand,” which is actually made of coal slag. 

Apart from being an easy-to-prepare option, this substrate won’t damage the glass or leave cuts on your hands. Not to mention how this is an excellent option if you want your tank’s shell dwellers to dig in and breed more. 


Here’s where you can get creative. From reefs and vegetation to rocks and decorative pieces, there are endless options for accessorizing your aquarium. While some aquascapers liberally add accent pieces for the aesthetic factor, fishkeepers may find that underwater caves and rocks provide snug hiding quarters for their fish.

As a finishing touch, you can opt for the Koralia Nano 425 Aquarium Circulation Pump from Hydor to recreate the gentle current of rivers and streams. This compact, low-energy nano pump can be positioned freely anywhere on an acrylic or glass tank with the patented magnetic-suction pump.

40 Gallon Breeder Tank Stocking Ideas
Photo: Ecopot

Final Thoughts

40-gallon breeder tanks have been receiving love from all kinds of aquarists — not limited to breeders. After all, these convenient tanks are affordable, convenient and add a sleek design element to your space.

If you’re considering getting one for your pet fish, be sure to research the fish’s needs and add the appropriate substrate, accessories, and devices. Similarly, reef keepers must ensure proper water conditions and lighting for sustaining healthy and mesmerizing reefs. 

As for breeders, this tank is a no-brainer as it allows them to “fish” out the swimmers with ease!

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Jeff Colt

Jeff Colt

Hello, I'm Jeff- an aquarium enthusiast with over 25 years of experience caring for a wide array of tropical fish, including koi, goldfish bettas, cichlids and more! For me: Aquariums are like jello - there's always room for more!

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