Guppies are sociable fish that don’t like to live alone. If you were to keep a guppy alone, it’d become prone to boredom, anxiety, and even depression.
Several fish species can be kept successfully with guppies in a community aquarium, and guppies also like to be kept in groups with their own kind.
But these livebearers are notorious for reproducing at unmanageable rates! So how should you keep them in groups? Let’s find out.
Guppies Are Social Fish
Although, strictly speaking, guppies are not ‘schooling fish’, they are social fish. If you’ve kept a group of guppies, you’ll know how much they enjoy interacting and chasing each other around the tank, especially when you keep boys and girls together!
A guppy kept on its own would be a very sad sight, and a single guppy fish would likely get bored, lonely, stressed, anxious, and even depressed.
Guppy Loneliness and Stress
Since guppies need stimulation, a single guppy will be prone to loneliness. This has many more consequences than merely psychological suffering.
Just like us, the mental well-being of your fish affects their physical well-being too.
If your guppy is stressed his or her immune system will become compromised, opening up the opportunity for all kinds of pathogens to take hold.
Parasites such as ich and velvet, as well as bacterial infections, often lie dormant in the tank, waiting for a weakened fish to strike. If your guppy is stressed or depressed, it will become a much more likely candidate.
Minimum Tank Size for Guppies
If you’re thinking about keeping a single guppy, maybe it’s because you want to keep one in a super-tiny tank. That’s not such a good idea.
Even though each guppy only needs 2 gallons of water per fish, you should never keep just one fish in a tank so small.
Tanks of less than 5 gallons have notoriously unstable water chemistry, and keeping a lone fish in such a small space would be cruel.
A 5-gallon tank for 3 guppies is the absolute smallest size tank, and the maximum stocking density you’d want to keep guppies in. And a 10-gallon community tank would be much better.
Keeping Guppies With Other Fish
Guppies will probably be happiest when kept with at least a couple more individuals of their own kind. But other fish species can also make good tank mates for them.
As long as they are not too big, and have a peaceful temperament, there are many fish and invertebrates you can keep with your guppy or guppies.
Good Tank Mates for Guppies
Suitable tank mates for guppies include other small, peaceful fish such as tetras, minnows, corydoras catfish, and danios.
Other livebearers like platies and swordtails also make good tankmates, but caution is advised if introducing mollies to a guppy tank, since mollies and guppies can breed together!
This isn’t always a good idea, and you can read more about the problems associated with cross-breeding mollies and guppies in my article here.
Incompatible Tank Mates for Guppies
With their small size, and long, delicate tails, guppies are fairly vulnerable to being attacked by other larger or more aggressive fish. Some people even breed guppies to feed their carnivorous pets!
Most cichlids, including angelfish, are not recommended to keep with guppies, nor are goldfish, freshwater aquarium sharks, or fin-nippers like barbs a good match.
Even small aggressive fish such as male bettas have been known to attack guppies, although some people have reported fewer problems when keeping female betta fish and guppies together.
Keeping Two Guppies Together
Two isn’t the best number of guppies either. You see, guppies love to make more guppies.
If you put a male and female together, you’ll soon have not just a couple, but a couple of hundred guppies to contend with! Fine if you have a 50-gallon tank, but definitely not for nano tanks!
Two males are also not a good choice. When kept without females, male guppies can become quite frustrated and aggressive.
Although keeping a larger number of males together is possible, if you keep just two, the stronger male will constantly harass the smaller one. If you didn’t intervene, the smaller one could easily die.
Keeping two female guppies together is better than the other options, but two females kept alone might also bicker and squabble, depending on their temperament.
Female guppies also tend to be less colorful, with less fancy fins than males. Sometimes, female guppies can even be pregnant when you buy them, but more on that in a moment…
The Ideal Number of Guppies
So if guppies shouldn’t be kept alone or in pairs, then what’s the best number of guppies to keep?
Guppies can be kept in groups of 3 or more, and it’s recommended to keep them at a specific sex ratio for the best chances of a harmonious outcome.
Guppy Male: Female Ratio
Most experienced guppy keepers advise keeping guppies at a ratio of 1 male: 2 or 3 female fish. This gives each male the satisfaction of multiple females to pursue, therefore lessening the chances of territorial or hierarchical disputes between them.
The trouble with keeping male and female guppies together is that (as you know by now) they love to breed! These livebearers are sometimes known as the ‘millions fish’ because of their prolific breeding habits.
Did you know a single female can deliver up to 2000 guppy fry in her lifetime? Now that’s a lot of baby fish to find homes for!
How To Prevent Guppies Breeding
Keeping an All-male-Guppy Tank
One way to eliminate the problem of over-breeding is to keep a tank of only-male guppies. As I mentioned, a pair of males may fight to the death, but when kept in larger groups, it’s possible to establish a peaceful situation.
The key to keeping male guppies together peacefully is to provide them with a large enough tank with plenty of hiding places.
Tall, dense plants, as well as rocks and caves, help to divide the tank up so that each fish can assert his own territory, and retreat from harm’s way if necessary.
You’ll still have to keep a close eye on an all-male group of guppies though and be willing to remove any troublemakers or smaller fish that are becoming targeted by larger males if necessary.
Keeping an All-female Guppy Tank
Female guppies are more peaceful fish than males and can live together more harmoniously in general.
Still, plenty of hiding places are recommended so that each girl can take refuge from more aggressive members of her group if necessary.
The main problem with keeping all-female groups of guppies is that they can be pregnant before you buy them! Yes, female guppies have the amazing ability to store sperm from a male for several months, and give birth to multiple litters from a single insemination!
This means if they were kept in mixed groups in the pet store, your females will likely already be pregnant when you buy them, and you’ll soon have a mixed group of more than a few individuals on your hands!
Reducing Stress in Guppy Tanks
As I mentioned, a great way to reduce stress and dangerous conflicts between your guppies is to introduce plenty of plants and hiding places.
But scientific research has also revealed some other interesting facts about stress in guppies.
Firstly, individual guppies have quite different personalities and responses to dealing with stressful situations.
Secondly, scientists found an excellent way to reduce stress in guppy tanks is to increase their intake of vitamin C! Using vitamin-rich brine shrimp, it was discovered that guppies fed on this diet suffered fewer stress responses than guppies in the control group.
Experienced aquarists probably won’t be surprised by these results, since fish fed with plenty of live and frozen foods tend to be noticeably more happy and healthy than those fed purely on dried food.
How Long Do Guppies Live?
If you’re thinking about keeping guppies, another important question is to ask about their lifespan.
Guppies are some of the shortest-lived aquarium fish and typically only live for around 2 years, with 3 years being the absolute maximum.
Since their lives are so short, it’s worth giving them the very best environment you can offer for them to live a fulfilling existence.
A happy guppy is also a healthy guppy, and fish that are active and well-stimulated are less likely to suffer from health problems and more likely to live longer than fish that are bored and lonely.
Guppies are sociable fish that do much better when kept with other tank mates.
Although you could keep a lone guppy with other species of fish, they’re more likely to feel fulfilled when kept in the company of other guppies in groups of 3 or more.
To find out more about caring for this ever-popular aquarium fish, check out our guppy care guide here.