40 Gallon Breeder Tank (Best Tanks, Stocking Ideas and More)

Whether you have had some experience with breeding before or you want to try breeding in larger tanks, a 40 gallon breeder tank is just what you are looking for.

There are a wide variety of beautiful fish that can be kept and bred in this tank, including both marine and freshwater species.

This guide will talk you through the best tanks available, and which fish are ideal to breed in a tank of this size.

Keep on reading to learn the ins and outs of breeding fish in a 40 gallon tank.

All About The 40 Gallon Breeder Tank

Breeding fish is no simple task! It takes a lot of time and skill to understand what is best for your fish, under what conditions they tend to reproduce and how to maintain an optimal environment.

It is especially challenging if you have never had any experience with breeding or keeping a large tank.

The most important thing to keep in mind when choosing a tank is the size of your fish.

Obviously, to breed smaller fish you don’t require a tank as big as 40 gallons, but the more space your fish have the happier they will be.

A 40 gallon tank is a relatively large space suitable for breeding a wide range of species, including well-known tropical favorites and reef fish. It can be set up both as common breeding grounds and a species-specific tank.

By far the most popular option in tanks of this size is to breed large fish. This tank will provide enough space for breeding fish, such as Bettas, Guppies, Clownfish, Plecos or Cichlids.

Don’t feel restricted only to fish though. This tank will provide an ideal environment for invertebrates, including Ghost, Amano and Cherry shrimps.

Other breeding choices in tank like this include Driftwood Catfish (Auchenipteridae family), Armored Catfish or Corydoras.

40 Gallon Breeder Tank Dimensions

Exact dimensions of each tank will vary, however most of the tanks will be 36 inches in length, 18 inches in width and 16 inches in height (36 x 18 x 16).

Usually regular (non-breeder) 40 gallon tanks will be slightly shorter in height and much longer.

However, breeding sometimes involves alterations in water level, so the dimensions of a breeding tank differ – they are often taller.

40 Gallon Breeder Tanks Reviewed

Best Tank

Aqueon 40 Gallon Breeder Tank
Aqueon 40 Gallon Breeder Tank

This glass tank is ideal for those people looking for a tank only deal which you can add all your own equipment to.

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The Aqueon 40 gallon breeder tank is perfect for all aquarists, from beginners to experts.

Made from a high quality and durable glass, this tank has smooth silicone edges to prevent any leaks. It is a solid and sturdy tank which would make a great breeder aquarium.

Aqueon are a well-known brand within the aquarium industry, they produce these aquariums in many different sizes and styles.

This particular size is available with a black or oak trim. It has been constructed with a brace across the middle of the tank to prevent the glass from bowing.

The dimensions of this tank are 36 x 18 x 16 inches.

  • Good height means you can alter water levels for breeding.
  • Tank only package allows you to add your own equipment.
  • Comes in either black or oak trim.
  • Aqueon known in the industry for producing quality products.
  • Quite expensive for just the tank.
  • Finding a lid that fits can be difficult.

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Best Tank Set

SeaClear Aquarium Combo Set
SeaClear Aquarium Combo Set

This 40 gallon breeder combo set comes complete with the tank, a reflector and an electrical lighting fixture.

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Unlike other glass tanks, this SeaClear 40 gallon breeder tank is actually made from acrylic – making it stronger, clearer and lighter than the equivalent glass tank.

Acrylic tanks are more impact resistant and much less likely to crack or chip than glass. This makes them an excellent option for breeder tanks which are constantly monitored and checked on.
This tank can be used for either saltwater or freshwater setups.

This combo set comes with a reflector and a 24 inch light fixture.

SeaClear offer one of the industry’s most extensive warranties, some tanks even come with a lifetime warranty.

This tank measures 36 x 15 x 16 inches.

  • Acrylic is stronger, lighter and more impact resistant that glass.
  • It comes with an extensive warranty.
  • The corners are seamless making visibility for breeding easier.
  • Tank comes with three different background choices.
  • You need to buy your own lighting.
  • The tank only has two small openings at the top – making cleaning tricky.
  • Acrylic typically scratches more easily than glass.

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Best Bow Front Breeder Tank

SeaClear Acrylic Tank
SeaClear Acrylic Tank

This tank is slightly larger than the regular 40 gallon breeder tank, with a unique bow-shaped front.

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This tank is a convex shape which enhances the view you have into the tank, making it ideal to keep a close eye on breeding, eggs and fry.

It can be used for either saltwater or freshwater setups, and has invisible seams only adding to the already great view you will have of your fish.

SeaClear are well known within the aquarium industry and offer a lifetime guarantee on their tanks.

  • Unique bow-front design.
  • Seamless corners which make viewing easy (ideal for breeding).
  • Acrylic holds the water temperature better than glass.
  • This tank is also much less likely to break or chip than a glass tank.
  • The top is only partially covered.
  • Acrylic scratches more easily than glass.
  • You will need to buy your own lighting.

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40 Gallon Breeder Tank Equipment

15 Gallon Tank Filter

The equipment in a breeding tank plays an increasingly important role, as fry and juveniles are most affected by changes in the environment – so picking the right equipment is essential.


The filter is vital for any normal fishkeeping tank, let alone specialized breeding ones. It helps create and maintain a healthy environment in the tank by getting rid of waste.

It also redistributes nutrients in the tank to establish a well-functioning cycling.

A filter is important because it can create regulated flow in the aquarium. The ability to regulate water flow is very important to breeding certain species, so don’t overlook this aspect.

Our favorite filter for a 40 gallon breeder is the Fluval.


The temperature is another important aspect of the aquarium environment. A good heater keeps the water temperature consistent. During spawning season and breeding itself, this can be especially important.

At the time of breeding, some species become overly sensitive even to the slightest changes in the environment. And some species won’t even start spawning until the water becomes warmer.

When choosing a heater, always check the required temperature for the species you want to breed beforehand. As some fish might require two different temperature ranges for breeding, getting an adjustable heater is a good decision.

Our favorite heater for a 40 gallon breeder tank is the Fluval.

Breeder Tank 2


Tank stands are used by almost everyone, as they provide stability and also act as good decorations in nearly any kind of interior.

The stand also provides enough storage space for all your equipment, foods, chemicals and plumbing.

They come in all shapes and sizes, so you will easily be able to find the right one. The only downside is that an aquarium with a stand will inevitably take up a lot of space. Make sure you have enough space before getting one.

Our favorite stand for a 40 gallon breeder tank can be found here.


The aquarium lid is an essential piece of equipment for every breeding tank. It comes in many variations and has many purposes. It can shelter the fish from excessive light – this might be especially useful as many juveniles require a slightly dimmed setting.

Other than that, a 40 gallon breeder tank hood can help you make sure that your fish stay inside the tank. This is needed with species that become easily stressed and start jumping out of the water.

What Fish Can You Breed in a 40 Gallon Tank?


A 40 gallon tank provides an ideal playground for breeding – this size allows you to breed some of the most challenging species.

You can breed almost any kind of small fish in 40 gallons, and some larger species too. Whether you decide to setup a freshwater or marine aquarium, there are lots of fish to consider.

If you choose to breed smaller fish you might want to use dividers to split the tank into two or three sections to give you more options.

Examples of small freshwater fish include Guppies, Danios, Swordtails, Bettas and Gouramis.

Some of the best larger freshwater fish include Giant Danio, Corydoras, Bala Shark, Oscar Fish, Red-tailed Black Shark or Headstander Fish.

Other choices include Armored Catfishes or Porthole Catfish. You can also include a lot of different Cichlids, such as Midas Cichlid or Parrot Cichlid.

If you want to try something a little more exotic, why not consider getting some crustaceans? Some that you may get are Ghost or Cherry Shrimp.

What is good about large tanks like this is that you can combine all sorts of fish, given that they can be kept under similar conditions and have enough space. This will not only make your aquarium beautiful, but very productive as well, as fish will actually produce offspring.

Make sure that you check the breeding conditions for every species that you are planning to add to your tank, to make sure they are compatible.

How to Setup a Breeder Fish Tank

Breeder Tank

The process of setting up a breeder tank is slightly different and will need you to pay a bit more attention.

Now that you have got your tank, wipe it down with water to remove any dust or build up. From now on all the steps are dependent on the species that you plan to breed in the tank.

The most important part of any aquarium are the filtration system, heater, substrate and lighting. In an ordinary tank the conditions remain unchanged most of the time, breeding aquariums may require slight adjustments from time to time – keep this in mind.

First you need to add the substrate. Check that it does not have any sharp edges or anything else that can hurt the fish. The chances are the juveniles will spend the majority of their time swimming close to the bottom.

Now that the substrate is in place, we move on to the decorations. The choice of decorations depends entirely on the fish you keep. Some fish need densely planted aquariums with plenty of rocks to breed, while others may just need a lot of free space and a soft substrate.

Once you have placed the substrate and decorations, it’s time to install the filter and the heater. How exactly you do that depends on the type of filter/heater. External filters require some space for plumbing inside the tank, whereas internal ones typically only have a power cable.

Now you will need to fill the tank with water. The appropriate water level also depends on the type of species in the tank. Some may require very shallow conditions during mating and an increase in water level later on to stimulate spawning.

What is left now is to install a hood with a lamp. Some hoods come with lights attached and other don’t.

Once your tank is set up, you can switch the equipment on and allow 4-6 weeks for the tank to properly cycle before adding your fish.


SeaClear Aquarium Combo Set
SeaClear Aquarium Combo Set

This 40 gallon breeder combo set comes complete with the tank, a reflector and an electrical lighting fixture.

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The 40 gallon breeder tank is an outstanding choice for any aquarist who would like to start breeding fish.

All the essential pieces of equipment can be found in any store or bought online. The specific equipment required (filter, heater etc) will depend solely on the fish you want to breed.

A 40 gallon breeder tank is a wonderful choice if you have always wanted to try breeding.

Let us know in the comments section below which fish you want to breed…

About Robert 202 Articles
Robert Woods is the creator of FishKeeping World, a third generation fish keeper and a graduate in animal welfare and behavior. He is also a proud member of the Association of Zoos and Aquariums, the Marine Aquarium Societies of North America and the Nature Conservancy.

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