Guppies have topped the list of best-selling tropical fish for over 40 years, and it is easy to see why they are so popular. Guppies are colorful, hardy, and super easy to breed. It is the ease with which they can be bred that often attracts new fish keepers to guppies.
For almost my entire fishkeeping career, which spans over 30 years, I have been keeping, showing, and breeding guppies. One thing I have learned over that time is that if you want to save the baby guppies from being eaten, you need to separate the mother guppy before she gives birth.
In my experience, one of the best ways to separate the female guppy prior to her giving birth is by using a breeder box. Breeder boxes typically float or are suspended in the same tank the guppy would normally live in, so the heavily pregnant female does not have to endure the stress of being moved to a new tank.
There are many different breeder boxes on the market, and they all work on the same basic principle which is to move the female guppy somewhere safe where she can give birth without the risk of the other fish eating her babies.
In my opinion, the following 5 breeder boxes are the best ones currently available. At one time or another, I have used each of these breeder boxes so I will try to share my insights with you so you can make an informed decision on which breeder box is right for you.
1. Fluval Multi-Chamber Holding and Breeding Box
The Fluval Multi-Chamber Holding and Breeding Box has been designed to create the perfect environment for your female guppy to move into a day or two before she gives birth. Rather than floating in the tank, this breeder box actually hangs on the outside. It looks and feels very much like a hang-on-back filter.
This breeder box is essentially divided into two sections, each separated by a v-shaped piece of acrylic which has slots cut into it that allow the baby guppies to pass through, out of reach of the female guppy, who is likely to eat them.
As this box is not actually in the aquarium, it uses air to lift the water up a pipe from the aquarium, into the breeder box, where it circulates before passing back out an overflow pipe, returning to the main tank. In my experience, this breeder box is the best one on the market for the way it makes sure the breeder box is always full of clean, water.
There is one thing I should point out that I learned from bitter experience. The outflow from this breeder box, which returns water to the main aquarium, has a grid to stop the baby fish from getting washed back to the main tank. However, the slots are large enough that very small babies can slip through, meaning they end up exactly where you don’t want them, which is in the main tank.
To solve this problem, I just place a small piece of sponge where the outflow pipe is. That way, water can still flow out, but babies can’t
This breeder box holds around 0.3-gallons (1.3 liters) which is enough space for a single female guppy. I have found that once the female guppy is returned to the main tank, the babies can live in this breeder box for around 3 weeks before they need a bit more space.
The good thing is, because of the way the water comes in from the main tank, they are better off than if they were living in a separate breeding tank of equivalent size.
The Fluval Multi-Chamber Holding and Breeding Box has been around for about 10 years and has been used by many thousands of fish breeders around the world. I myself have about a dozen of these breeder boxes in my fish room. At less than $20, I think this is a great breeder box, especially for those who are breeding guppies for the first time.
One thing to be aware of is this breeder box does require a separate air pump to physically move water from the main tank into the breeder box. If you don’t already have one you will need to get one.
2. Ziss BL-2 EZ Breeder Box
Whereas the Fluval breeder box above sits on the outside of the tank, the Ziss breeder box sits inside the aquarium. This breeder box is one of the newest models on the market and Ziss has worked hard to design the ultimate Guppy breeder box.
The Ziss breeder box is made of acrylic and the bottom and two of the sides are made from fine mesh which allows water to circulate freely throughout the breeder box without letting the baby guppies escape.
Much like the Fluval breeder box, this breeder box uses a separate air pump (not supplied) to draw water from the main aquarium into the breeder box.
There are two different ways the Ziss breeder box can be suspended in the aquarium. Firstly, it comes with a couple of suction cups that attach to the breeder box so you can stick the box directly onto the glass anywhere in the aquarium.
The second method for fixing is using a hanger that hooks over the aquarium glass. The hanger has a thumbscrew, allowing you to tighten it no matter how thick your aquarium glass is. The hanger is also adjustable so you can make sure the breeder box sits perfectly in your aquarium.
This breeder box comes with a top to prevent the guppies from jumping out. The top has a feeding hole cut into it, meaning you don’t need to remove the lid to feed your guppies.
In my opinion, the Ziss breeder box does have one major downside, and that is the price. It currently retails at just over $100, which is a lot of money, however, this is a quality breeder box that will last for many years.
I currently have two of these breeder boxes in my fish room, and I do believe they are worth the money.
3. Capetsma Fish Breeding Box
The Capetsma Fish Breeding Box is a much simpler piece of equipment than the previous two breeder boxes I have looked at.
This breeder box is made from acrylic and has been designed to hold either one or two pregnant guppies prior to them giving birth.
Much like the other breeder boxes on this list, the basic principle is that the female guppy gives birth and the young quickly swim through the grates into the fry safe area where the other fish can not eat them.
The Capetsma Fish Breeding Box is held in place by two suction cups that stick directly to the aquarium glass. This breeder box can be placed anywhere inside the main tank. As there is no mechanical way for water to circulate inside this breeder box, I usually place them near the filter outlet so the movement of the water returning from the filter helps circulate the water inside the breeder box, preventing stale areas.
If you would rather, this breeder box can be left free-floating in the aquarium rather than stuck to the sides.
This breeder box has a central divider that can be used or removed depending on if you want to house one female guppy or two. Personally, I just have one female in mine at a time as I find it a bit small for two guppies.
As these breeder boxes are so cheap (typically under $10) I use a lot of them. In fact, when I look around my guppy breeding tanks, I probably have more of these breeder boxes than any other ones.
4. Petzilla in-Tank Aquarium Breeder Box
With this breeder box, Petzilla has worked hard to come up with an innovative design for the classic breeder box. They have created almost twice as much space inside the breeder box by making the whole thing much taller than similar models on the market.
In my experience of using breeder boxes, this almost double-decker style of breeder box works better for both the female guppy, who has more space in her section, as well as the babies.
The Petzilla breeder box follows a similar design to some of the others on this list in that it uses a separate air pump to create water circulation within the breeder box. This circulation helps prevent dead spots or stagnant areas from forming within the breeder box.
I have found the best way to secure this breeder box in place is with the two suction cups provided. The internal divider can be used if you want to house two pregnant guppies, or removed if you just have one female. I find it a little small for two fish, so I only ever house one female in it at a time.
Which is the Best Guppy Breeder Box?
Best is always a hard choice to make. If money were no object, then the Ziss breeder box would be my go-to every time. However, at more than $100 a pop, they are not for everyone.
I really like the Petzilla breeder box too. It not only looks good, but I have also found the babies naturally drop down into the fry saver section, then rarely return to where the female guppy is thanks to the unique wave-like design of the horizontal divider.
Downsides of Using a Breeder Box
I think it is fair to say, using a breeder box is not without its downsides. Many breeders agree that moving a heavily pregnant female guppy into a breeder box just a day or two before she is due to give birth is very stressful for the fish.
In my own experience, I have known female guppies to give birth to an entire brood of dead babies, probably because she was so stressed by the move.
Also, being placed in a floating, clear box exposed to all the other fish is in itself stressful for the female guppy. Under normal circumstances, the female may try to hide away at the point of giving birth. Choosing to have her babies either behind a decoration or in a clump of plants.
We can help mitigate this stress by placing live or fake plants in the breeder box with the female. In the past, I have put clumps of Java Moss or Hornwort in the breeder box with the female. That way she at least feels less exposed.
Alternatives to Breeder Boxes
If you don’t already own a breeder box, or you have had a bad experience using one, you might prefer to look at some of the other options available.
I have had good success in the past leaving my female guppies in the main tank but adding lots and lots of live plants. If you can create thick clumps of plants, the baby guppies have somewhere to hide immediately after birth. Guppies have an inbuilt natural instinct to swim to cover the minute they are born. Apart from anything else, this prevents the female guppy from eating her own babies.
Java Moss is a plant used by professional breeders the world over. The moss creates a thick mass that the babies can get into but the adults can’t. Water Sprite and Hornwort are also plants that work well in breeding tanks.
Another viable alternative to a breeder box is to set up an entire separate tank for the female guppy to give birth in. It doesn’t have to be a large tank. I have used 5-gallon (22 liters) tanks with small sponge filters in the past.
Although a separate tank doesn’t get around the issue of moving a heavily pregnant female, at least once she has been moved she is in a good-sized space where no other fish are looking at her.
Using separate tanks is always my preferred method for saving as many baby guppies as I can, but it does rely on space and additional tanks being available.
DIY Breeder Boxes
If none of the breeder boxes on this list are quite what you are looking for then you could always make your own breeder box.
Recently I had cause to make my own breeder box. I simply took a small, rectangular container and cut a couple of large holes in the sides. I covered those holes with a fine mesh that I had in my fish room. I stuck a couple of pieces of styrofoam to the sides of the box using superglue gel.
The styrofoam kept the breeder box floating. I added a large clump of Java Moss to the breeder box and moved the female in. She gave birth within a day or so and I moved her back out to the main tank. It was a success.
DIY boxes work well, especially if you find yourself needing a breeder box at short notice.
Breeder boxes serve a purpose and certainly have their place in the hobby. If you find yourself with a pregnant female guppy and you are looking for a low-cost, easy way to save as many of the babies as you can, breeder boxes offer a great solution.
For the first-time guppy breeder, I would suggest going for a basic breeder box that is sized for a single female. If you are looking to breed guppies on a larger scale, then maybe consider a more advanced option like the Ziss breeder box.
Over the years I have tried them all, and they essentially all do the same job.