Skip to Content
Home » Fish Tanks » Current Page

What is a 40 Gallon Breeder Tank And Why People Use It

When people get carried away talking about our hobby, they start calling tanks “40 breeders” assuming everyone knows. To be honest, I didn’t and had to do some research to find out.

Quick Answer

A 40-gallon breeder aquarium is a fish tank with specific dimensions. Unlike other 40-gallon tanks that have a more rectangular base, breeder tanks have a bottom that’s more square. It’s designed for breeders to easily access their fish due to the lower profile. 

Keep reading to find out what exaclty a 40 breeder is, what makes it different from a regular 40-gallon tank, and more! 

Dimensions of a 40 Breeder Compared to Other 40 gallon tanks

Whenever someone is talking about a 40 Breeder, they’re talking about a tank that’s about 16” tall and not that wide. The exact measurements can vary based on what manufacturer you’re looking at.

As you can see in the image below, the 40 Long and 40 Breeder are equally tall. However, the 40 Breeder is way more convenient when you’re handling fish. Catching fish in a long tank can be a struggle when they’re fast and agile.

Besides these three varieties, there’s also a 40 Cube. All sides of the 40 Cube are around 20 ¾ “ to end up with 40 gallons. 

The lower profile of a 40-gallon breeder tank makes it easy for the fishkeeper to adjust the layout of the aquarium and handle fish. The ease of catching fish is the reason why these dimensions are called a breeder tank.

Why Would You Want a 40 Breeder Aquarium

There are many benefits of having a 40 Breeder. The low height in combination with the bigger footprint makes it easy to catch fish and handle fry. However, there are many people that own 40 Breeder tanks that never had the intention to breed any fish. That’s because of the other benefits.

First of all, when looking at the front of the aquarium, the tank’s very deep. You’ve got roughly 18” of space to fill with rocks, plants, wood, or ornaments. That’s much more than the average 12” of space you’ve got with “regular” 40-gallon tanks.

You really can get creative, and space offers a lot of room for different layers, additional interest, or larger rocks or pieces of driftwood.

It’s because of this reason that 40 breeders are popular among aquascapers. Aquascapers are people who create beautiful landscapes underwater (aquarium landscape).

Another group of people that’s very happy with 40 breeder dimensions are turtle keepers. I’ve got two musk turtles myself, and these varieties aren’t the best swimmers. Instead, they prefer to walk on the bottom of the tank and swim up for air occasionally. With a very tall tank, it gets harder for the turtles to swim up, which is the reason why many turtle owners prefer a lower tank height.

Where to Buy a 40 Breeder Qquarium

If you are looking to buy a 40 breeder tank, you have to check out this tank on Amazon. It’s the absolute perfect breeder tank and one of the most inexpensive (whilst still quality) out there right now.

40-gallon breeder tanks are popular, so chances are someone in your region is selling theirs. I would check that first, but make sure you look for obvious damage and thoroughly test whether the tank is watertight (preferable somewhere outside or in your garage, and not in your living room next to your television).

5 Different 40 Breeder Stocking Ideas

If you’re interested in potentially buying a 40-gallon breeder tank, you’ll want to know what fish you could keep and breed. There are many options, and the most popular option would be to convert the tank into a community aquarium.

I’d be a great option, as you have many options and can also grow a lot of live plants. If a community tank would be best for you, I’d recommend reading my list of 15 suitable community tank fish for you to pick from.

If you’re really going to use the tank for breeding, then I’m happy to tell you that the size allows you to really breed lots of different popular aquarium fish. Let’s jump straight into the first popular option to breed in these tanks!

1. Giant Danio

First up is a fish called Giant Danio. They are fish that display beautiful yellow and turquoise stripes and are breedable in a 40-gallon breeder. These fish are egg scatter fish and require fine plants or a spawning mob to induce them to spawn.

Overall a great option and something that you don’t often see. You’ll have to check with your local fish store whether you’re able to buy some of them. Just like with any fish, make sure to do your research beforehand. Other danios might make for good options too!

2. Corydoras Catfish

School of Bronze corydoras swimming in aquarium tank,Corydoras aeneus

Fish that are super popular in our hobby are corydoras. There are many varieties, and in your 40 Breeder you’re able to breed even some of the larger common varieties. These fish are great to breed, because the female fish is able to stick their eggs to the glass, to plants and to other ornaments.

If you’re successful with breeding corydoras, I’m 100% sure that your local fish store will be happy to buy them from you. There’s a high demand for these fish, and you’ll surely be able to get a couple of bucks in either store credit or (if you’re really serious and able to provide on a consistent basis) cash.

3. Long Tail Bristlenose Catfish

Fish that are popular and easy to breed are bristlenose catfish, also known as Ancistrus. When the female has laid eggs, the male fish will actually guard them until they have hatched. This means that it’s easy to get these fish to hatch when you’ve provided the right setting for them.

I’ve personally bred these fish in a dedicated small tube. It’s really a great fish to breed and there’s high demand so your local fish store will be extremely happy when you’ve got these fish and want them to take them off your hand.

4. German Blue Rams

Fish that are a little more difficult to breed but are most definitely worth the effort are German Blue Rams or GBR for short. They display phenomenal colors when a breeding pair is ready for babies. There’s a great video on Youtube where an experienced breeder explains how to get these fish to spawn. I’ll link it right here:

5. Livebearers

Finally the easiest option on this list, but most definitely not the least rewarding, are livebearers, the opposite of egg layers. There are many different and new fish for you to pick from.

Great options are guppies, mollies, platies, or swordtails. Because of the size of this breeder tank, you’ve got plenty of space for any of them, and in many cases they make for good tank mates too.

Get a ratio of 3 females for every male fish you get, feed them enough and provide some plants and you’ll quickly get babies. The livebearer parents can be tempted to eat their fry, so make sure you’ve got plenty of hiding spaces to allow the babies to get out of sight. You may also jut want to quarantine the fry for their own safety. 

Then there’s this great video from Aquarium Coop with some more stocking ideas for a 40-gallon breeder. He goes more into the larger fish options for you to keep.

Don’t Put These Fish in a 40 Gallon Breeder

While 40 gal is a lot of water that can house a lot of different fish, angelfish are not suitable for these breeder tanks. A 40 High, with a height of on average 20”, is able to house angelfish, but the 16” that the breeder tanks provide will not suffice. This fish species will scrape their fins on the substrate, causing injuries and fin rot.

My favorite fishtank products that make life easier

I am so happy you enjoy this post so far! You will also definitely like my product recommendations that will make your fishkeeping experience so much better. I’m 100% sure you’ll love them!

  • Without a gravel vacuum, like one from Aqueon, cleaning the substrate of your tanks is near impossible. Whenever I want to remove some of the sunken detritus from the bottom of my acrylic tanks I’m happy I’ve got one of these.
  • It’s no secret that I do not like nutritious aqua-soil. It makes a mess and only works for a given amount of time. Instead, I always use a liquid aquarium plant fertilizer. Everyone who keeps live plants needs it, it’s not that expensive and makes your plants grow better.
  • I love keeping plants, but planting and reorganizing my aquarium was difficult until I got a set of these tools. It’s much easier to plant any kind of plant compared to using my thick fingers.
  • Ever since I’m able to accurately test my water parameters, including the pH level, keeping fish became less stressful. Before I was always stressed that my water parameters were wrong, but with a kit such as the API Master kit, I can measure this. It really is essential to successful fishkeeping.
  • The more you know about your aquarium, the better! Temperature is crucial for the health of your fish. A thermometer will also show you whether your heaters are still working correctly. It will give you more insight and more peace of mind. It’s an easy way to ensure that you’re providing your fish with the tropical temperatures they need.