cichlid guarding fry in 40-gallon breeder tank

40 Gallon Breeder Tank: Buyer’s Guide

Fish breeding is a lucrative hobby and if you’re thinking about getting into the hobby of fish breeding, a 40 gallon breeder tank is a great place to start. Breeder tanks are often larger than your traditional tanks, but not as large as some of the monster tanks out there. They provide plenty of space for fish and help to create a safe, calm environment for your fish to reproduce. Our favorite 40-gallon breeder tank is the Aqueon 40-Gallon Breeder Tank. In this buyer’s guide, we’ll discuss the features that you should look for when shopping for a 40-gallon breeder tank, and we’ll recommend some of our favorite models. So read on to learn more!

Best 40 Gallon Breeder Tank Options:

What is a breeder tank?

Like the name suggests, a breeder tank is something aquarists use to breed fish. A breeder tank differs from a typical aquarium in that it lacks the extra features found on many display tanks. Breeder tanks are functional whereas display tanks are for maxing out your aesthetic appreciation. Another key difference is that breeder tanks are typically long, narrow, and relatively shallow. These are not bow front tanks. This helps the fish breeder have easy access to the breeding pair and young fry.

A breeder tank can help increase the chances of successful spawning because the fish are in a highly controlled, private environment. However, it is important to set up the tank correctly for successful breeding so we will cover breeder tank set-up in this article.

What is the best 40-gallon breeder tank?

Our favorite 40-gallon breeder tank is the Aqueon 40-Gallon Breeder Tank. It is a simple, glass tank from a reputable brand. Because it is just a tank, it allows for full customization of filters, heaters, and anything else you need for successful breeding.

What Size is a 40-Gallon Breeder Tank?

Although the exact dimensions may vary, a 40-gallon breeder tank’s dimensions are roughly 36†in length by 18†in height by 16†deep. The general tank structure is a narrow rectangle that is relatively shallow.

If your tank is glass, it will weigh approximately 55 pounds. An acrylic breeder tank with the same dimensions would weigh around 20 to 25 pounds.

Regardless of the construction material, we recommend purchasing an aquarium stand to support the weight of the tank when filled, which can easily reach around 450 pounds.

Where Can I Buy a Breeder Tank?

Breeder aquariums can be purchased at most local fish stores. You can also purchase them online through retailers like Amazon. We’ve outlined our favorite breeder tank choices online below. Another good tip for purchasing is joining a local aquarium group, where members often buy and sell used equipment. You will likely find other gallon tanks being used as breeder tanks (20, 55 gallons, etc.) but 40 gallons is a pretty common size.

Best 40-Gallon Breeder Tanks

Aqueon 40-Gallon Breeder Tank

Aqueon is a reputable fish tank brand so this is an excellent, quality choice. This aquarium is made from glass with smoothly finished silicone edges to prevent leaks. You can choose either oak or black trim. The tank has a brace across the center to prevent any glass bowing issues. The measurement of this tank is 36 x 18 x 16 inches.


  • Glass construction
  • Center brace to prevent glass bowing issues


  • Tank-only so easy to customize other elements of the set-up
  • Choice of trim colors
  • Reputable brand


  • Requires finding hood for covering tank
  • Expensive as a standalone tank

SeaClear 40-Gallon Breeder Tank

This breeder tank option is more of a complete kit, as it comes with a reflector and lighting fixture. It is suitable for both freshwater and saltwater fish breeding. It is also made from acrylic, so it is lighter and easier to move around your house if you want to change the location. It also comes with a lifetime warranty.

In addition to its acrylic construction, this aquarium has seamless corners. Seamless corners are typically more aesthetically pleasing than seams with trim, and it is also which easier to see tiny fry in the tank (which is the whole purpose of the breeding tank!). You can also use three different background colors to create additional contrast so it is easier to see your fish and fry.

This aquarium measures 36 x 15 x 16 inches.


  • Acrilyc construction
  • Measures 36 x 15 x 16 inches


  • Acrilyc is lighter than glass
  • Lifetime warranty
  • Choice of three backgrounds


  • Acrilyc is more subject to scratching than glass

Perfecto 40-Gallon PF Breeder Aquarium

This is a pretty straightforward breeder aquarium. It is constructed with high-quality, durable glass for a clear view of your tank livestock. Like the Aqueon option above, this tank has a central brace meant to prevent any glass bowing over time. This tank is silicone-sealed to prevent leakage. It also has a clean black trim so it looks nice in your house. This tank is suitable for both freshwater and saltwater breeding. It is also suitable for both canister or HOB filter systems. This aquarium measures 36 x 15 x 16 inches.


  • Glass construction
  • Measures 36 x 15 x 16 inches


  • Simple, basic aquarium breeding tank
  • Central brace adds to tank stability


  • Some owners reported issues with shipping damaging the tank

SeaClear System II Acrylic Aquarium

This SeaClear tank is an upgraded version of the Seaclear acrylic option above. In addition to a beautiful tank, this kit also comes with a filtration system that’s integrated into the tank design. This three-stage filter system houses mechanical, biological, and chemical filter media. The filtration system is quiet so you’re not going to listen to the filter run day and night. It is powerful enough to create sufficient circulation without spinning your fry in circle due to unnecessarily powerful flow.

If you need a protein skimmer or heater with this set-up, there is plenty of room for those also. The option is the standard breeding tank shape and measures 36 x 15 x 16 inches.


  • Acrilyc construction
  • Measures 36 x 15 x 16 inches


  • Filtration system built into tank
  • Effecient and quiet filter


  • Doesn’t include a heater or light bulb 

40-gallon breeder tank equipment

Choosing the correct equipment to go with your breeder tank is very important. Fry and breeding fish are sensitive to sudden changes in their surroundings so you need to make sure their environment is stable and dialed in. Below, we will explore a list of what you’ll need and we’ve included links to helpful and informative articles to learn more.

Filter system

Fish need clean water to thrive. If left unfiltered, their water will get progressively dirtier and saturated with harmful chemicals such as ammonia, nitrites, and nitrates. Because of this reason, a good filtration system is required for your tank.

Additionally, filter systems create water flow, which helps mimic the natural conditions of your fish. Be mindful of the flow rate though because too much water flow for fish used to slow-moving conditions (like some species of goldfish like the Bubble Eye Goldfish or Black Moor) can be stressful to breeding pairs and fry.

We typically recommend an external canister filter or HOB filter system. Some aquarists prefer a simple sponge filter so we recommend experimenting to find what works best for your set-up. Whatever you choose, make sure your filter intake includes a guard so it doesn’t suck up the small fry.


Water temperature is very important in a breeder tank. A lot of fish species need slightly warmer waters to get in the mood and start spawning. The warmer water replicates their natural environment breeding cycle as water is warmer in the spring and early summer when most fish breed. Makes sense, right?

In other words, you’re going to need a heater for your breeder tank. Get one that is adjustable so you can adapt to what your fish need. While you’re purchasing a heater, we also recommend a thermometer or aquarium temperature controller so you can more easily maintain a consistent environment.


The fish species that you’re trying to breed will have certain tank parameter preferences that will drive what you need for temperature, heating, and lighting. If you want to err on the side of flexibility, we recommend a lighting unit that creates both daylight and moonlight. This gives you max flexibility. Many species spawn early in the morning so depending on the lighting unit that you purchase, you could program a light sequence that resembles sunrise, thereby giving your fish another clue that it is time to spawn. You might also want to consider a natural-looking aquarium background to create a calming environment.

Tank divider

Some aquarium fish species (I see you Cichlids!) can get a little feisty immediately before or after spawning. If you’re preparing for a potentially contentious spawning, you can protect your fish with a tank divider. Tank dividers keep the fish in the same tank so they can see one another but physically separate them so they can’t get injured before spawning.

Some dividers can be installed with space underneath the divider that is close to a flat rock or spawning mop. This is a super safe spawning option where the female can lay eggs on the flat rock on her side of the divider and the male is able to fertilize the eggs underneath the divider from his side. This keeps them physically separate the whole time. The downside of this option is that fewer eggs might be fertilized but long term, your fish will stay a lot healthier.

Aquarium Stand

40-gallon breeder tanks weight a lot when filled with water – about 455 pounds. An aquarium stand is purpose-built for supporting the weight of the aquarium. We don’t recommend trying to make an old piece of furniture work; we’ve heard too many horror stories of aquariums crashing to the ground.

Setting up a breeder aquarium

Depending on the fish species you want to breed and its spawning habits, setting up a breeder tank is somewhat different from establishing a standard fish tank.

Bubble nesters

Bettas and gouramis are probably the most famous bubble nester species. Males will create a large grouping of bubbles, usually in a corner of the tank or around floating plants. The female then lays her eggs near the bubble nest, and both parents split the work to carry them to the nest.

If you’re breeding Bettas or Gouramis, this means you’ll want to give them floating plants that the male can choose as a nesting site.


Livebearers include Guppies, Swordtails, Platys, and Mollies. These species are super easy to breed. Most of the time, they’re almost continuously breeding and the bigger challenge is slowing them down! Another major challenge is that livebearers tend to be pretty bad parents who will eat their babies. Because of this, you will want to provide lush plants where the fry can hide until they grow large enough to be safe around their parents and other tank members.

Egg layers

Egg layers are the most challenging spawning type. Depending on the species, you might need to put a sandy substrate in your tank, while other species will prefer flat rocks or live plants to place their eggs. Research is the name of the game when breeding an egg layer species – know what they want, and recreate that in your breeding tank.

Jack Dempsey with fry in 40-gallon breeder tank

Tank lid

We highly recommend a tank lid for both your breeding tank and regular display tank. Breeding can make your fish pretty excited, which means they’re more likely jump out of the tank. Breeding doesn’t give them special abilities to breathe out of the water so this is a situation you want to avoid! We also recommend keeping the water levels a little lower in your breeder tank for the same reason.


Breeder tanks are functional tanks, meaning they’re meant to create a safe and healthy environment for breeding your fish. Most aquarist don’t invest the same amount of time and effort into the aesthetics of a breeding tank as they would a display tank. However, that doesn’t mean decorations are completely out of the picture. Decorations like rocks or terracotta pots create natural hiding spots for your fish and fry, helping keep stress levels down.

We recommend avoiding an airstone in your tank though. The bubbles can wreck havoc on bubble nests and eggs, which would be a terrible outcome after you invested so much effort in making the spawning happen.


We always love live plants in aquariums; they’re great for the water quality and create a beautiful, natural look. Breeder tanks are no exception. Plants like Java Moss and Anubias are some of our favorites. Many species use plants as spawning sites. Further, plants house microbes that can feed the fry as they grow up. Lastly, plants make great hiding spots for fry when they’re small. That being said, some fish species will uproot every plant you place, so know your species.


Again, substrate selection comes down to knowing the preferences of your breeding fish species. Egg buriers, for example, will need a sandy substrate where they can deposit the eggs. However, with some other fish species, you might not be required to add substrate.

The benefit of a bare bottom breeder tank is that cleaning is extremely easy. Additionally, it will be much easier to see the eggs and fry, so you’ll be better able to keep an eye on things.

Water parameters

Keeping consistent, stable water parameters is extremely important in your breeder tank. Sudden changes in the breeder tank can stress the parents to the point where they won’t spawn or kill the fry. For this reason, we recommend purchasing a water testing kit so you can stay on top of the water conditions.

To trigger spawning, a lot of fish species need slightly warmer water than usual. However, this doesn’t mean the temperature should be maintained at this elevated temperature. Reduce the temperature back to the species’ regular range once the eggs are laid and fertilized. If the water temperature is kept too high for too long, the eggs will either die or develop too fast. If they still end up hatching, it could also cause development issues for the fry.

Water changes

As you might have picked up on by now, fry are sensitive little creatures. They need stable and consistent water conditions to thrive. Fish waste, if left to accumulate, can be dangerous for the fry.

For most fish species, we recommend doing a 25% water change in the breeder tank on a daily basis. We also recommend feeding small quantities of live food and regular vacuuming of the tank floor to keep ammonia accumulation down.

We also recommend a few other tank maintenance items such as an algae scraper and aquascaping pruning kit to keep your tank in ideal condition.

Can a 40-Gallon Breeder Tank be Used for Turtles?

If you want to totally deviate on your breeder tank and are considering using it for a turtle, it can be done. However, the turtle will have to be quite small. The typical rule of thumb is 10 gallons for every inch of your turtle, which translates to a 4 inch turtle max. If you’re interested in learning more about turtle tank sizes, check out our turtle tank guide.


A breeder tank can be customized to fit the needs of your fish species and it is a great way to help your fish spawn and raise fry. Whether you’re looking for help setting-up or purchasing, we hope this guide has been helpful! If you have any other questions about breeder aquariums, feel free to reach out anytime. We want to hear from our community members as well – what experience do you have with breeding tanks? Did they work out for you? Let us know in the comments below!

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