Guppy Care Guide: Lifespan, Size, Feeding & Breeding

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Guppies are a staple of the aquarium trade. Their fantastic colors and easy care make them one of the most popular aquarium fish. There’s still a little bit more to it than just dropping them in a tank and hoping for the best.

Ready to learn? Let’s dive right in with the information you need to make guppy care a breeze.

guppy

Guppy Quick Care Sheet

  • Common Name: Fancy Guppy
  • Alternate Common Name(s): Millionfish, Rainbow Fish
  • Latin Name: Poecilia reticulata
  • Care Level: Super Easy
  • Tank Size: 10 Gallons+
  • Size: Male 1 ½”, Female 2 ½”
  • Diet: Omnivorous
  • Behavior: Peaceful
  • Lifespan: 1-3 years
  • Reproduction Type: Livebearer 
  • Water Temperature: 74°-82°F (22°-28°C)
  • pH: 7.0-8.0
  • Water Hardness: 8-12 dGH

Origins of the Guppy

Guppies can seem boring, but they’re actually one of the most studied fish in the world. They originally hail from the northeastern portions of South America, where they’ve been found in every appropriate waterway. The first ones were found on Trinidad, but the fish had already been described on the mainland before their official discovery.

Guppies are incredibly adaptive fish. They’re now found in every waterway that someone foolishly placed one. Their environmental impact is low in most areas, but in places like Hawaii, they’ve been implicated in some serious ecological problems.

The true history of the modern guppy begins in aquaria, however. They didn’t seem to be of much interest to scientists but eventually, they got around to looking at the samples. After some studying, they quickly acquired a total of 11 scientific names, mostly dependent on the genetic strain of the specimens received. Their current scientific name, Poecilia reculata, wasn’t decided on until the middle of the 20th century. 

In 1908 the first live guppies made it to Europe. Their hardiness was tested, the primitive method of trying to avoid foreign diseases meant that all arriving goods were sprayed with noxious chemicals. Many died, but the ones that remain quickly became a hit for those keeping aquaria.

The Germans nicknamed them the millionfish for their ridiculous rate of reproduction. Within a bit more than a decade there were formal rules for judging guppies and by 1954 there was an actual society dedicated to their care. 

They mutate and produce new colors and fin variations quite easily. Their appeal is easy to see, Betta splendens went through a similar popularity boost for the same reasons.

You’d be wrong to lump in the humble Guppy with the majority of South American fish, however. Most of us are used to making acidic, soft water tanks in order to mimic the environment but guppies prefer a high pH and hard water.

Guppies can actually be acclimated to brackish or even full saltwater conditions. I’ve even seen them used to cycle saltwater tanks.

These hardy, beautiful fish are a staple of the aquarium hobby. They’re often the first fish someone gets. My first tank was full of clown-puke gravel, plastic dinosaurs… and a group of 12 Fancy Guppies.

The bottom line is that guppies are easy to care for and have been in the aquarium trade for over 100 years. They may be looked down on by some, but their staying power is impossible to argue with and there are still guppy shows in countries all over the globe.

Ideal Tank Setup and Care

You’ll be fine with pretty much anything for guppies, but some basic principles can make their care a lot easier. The following are suggestions, any cycled tank with appropriate equipment and no predators is a good arrangement for these fish.

Aquarium Equipment

Standard equipment for the tank will do. You just need the following:

  • HOB or Canister Filter
  • Heater
  • Air Pump (Optional but recommended)

These will get you going without any issues. You can just read the tank size on the box. Guppies don’t mind higher flow but don’t overdo it with powerheads either.

You may want to set up for plants as well, especially if you don’t want to bother with a breeding tank. Thick vegetation can help protect fry from cannibalism until they’re big enough to join the rest of the school.

Hiding places are always a good idea as well, just create a few caves with your hardscape elements.

If you’re looking for something more simple… well, guppies thrive in aquariums. You can use colorful gravel and plastic decorations for the tank as well.

Plant Suggestions

Guppies won’t eat plants so you can put whatever you’d like in there. I tend towards protecting the fry as much as possible to avoid having to set up another breeding tank so I go with a lot of thick plants to create a jungle atmosphere.

Some good cover plants include:

  • Anacharis
  • Hornwort
  • Java Moss

The latter is particularly useful. Tie it to a hardscape element and let it grow to the top of the water line and you’ll have an ideal protective barrier between the adults and fry when the guppies breed.

Cycling

Guppies can survive cycling in a tank most of the time. I’ve never had a loss when I’ve done it, but I still advise against fish-in cycling. That said, if any fish is a decent candidate for dealing with cycling… well guppies are it.

You can either put the guppies into the tank while it cycles and watch them closely or cycle the tank as normal.

Cycling, for those new to the hobby, is an easy process. You just need to get the bacteria that handle waste to build up in the tank by supplying them with food. Airborne bacteria will settle and handle the rest.

I’ll outline the process with a caveat: if you have fish in and your aquarium tests positive for nitrite or ammonia you should perform an immediate 30-50% water change to protect them.

  1. Add food to the tank daily. A tiny pinch will do it.
  2. Test for ammonia daily, or twice per day if you have fish in the tank. Ammonia should show after 1-3 days.
  3. Begin testing the tank for nitrite daily. Keep testing until nitrite readings don’t show up on the test.
  4. Test until nitrates show up and lower a bit. 25ppm or less will be fine for guppies.

This process will give you a biological buffer in your filters. These helpful bacteria are one of the keys to successfully keeping fish. They convert extremely toxic waste into fairly benign nitrates. 

Without them, we’d be doing huge water changes on a daily basis.

Feeding

Guppy will readily take flake, pellets, and all of the other forms of processed fish food available. They’re not very picky eaters.

That said, color-enhancing flake should be a staple. The carotenoid in it causes the coloration of guppies to improve, creating a much healthier-looking school.

I also offer frozen foods once a week or so. Bloodworms are another good option, especially since they tend to enhance the colors of fish.

The takeaway is they can eat anything and be healthy but color-enhancing foods are best to keep them healthy and beautiful.

Show Guppies vs. Store Guppies

The guppies that you find in stores aren’t from the same genetic line as carefully bred show guppies.

Show guppies are far more expensive, and a little bit more fragile, than their counterparts. They’ve been bred to meet exacting specifications of their type. Good breeding results in beautiful, healthy fish.

Store guppies, on the other hand, are bred a bit haphazardly so you end up with tanks full of multiple colors.

I’m a big fan of the guppies from my LFS, but I also have no interest in fish contests. If you’re looking to breed a winner then it’s best to start with good genetic stock from a show guppy line. I just prefer having a tank full of haphazard colors and patterns.

It’s just something to be aware of. If you’re looking to breed guppy for contests or demand “perfect” fish then you should look for a breeder that sells mated pairs of show guppies. For the rest of us the LFS will do just fine, and these fish are generally more hardy overall due to extensive, random outbreeding.

Suitable Tank Mates

Guppies are able to get along quite well in community tanks. They’re a staple in community tanks and it’s just a matter of finding fish that won’t eat them.

Protecting fry can be a concern, small fish can and will eat them. Heavy decorations or plants will be required to keep the population relatively stable.

You can keep guppy with the following species with no issues:

Guppies don’t spook easily with fast-moving fish in the tank like some smaller species. Of those species listed only Zebra Danio will eat a significant amount of guppy fry, but they’re not good at getting into tight spaces.

The following species are more likely to eat fry but still make good guppy tank mates:

Now, this is a list of species that I have personally kept with guppies. The list of good companion is much longer. Most invertebrates will also be fine with them, barring the more aggressive large species like red-claw crabs and crayfish.

But a word about fish that aren’t guppy safe is still needed.

Obviously, these fish don’t belong in a cichlid tank, but I’ve seen more than one school slowly disappear because someone kept them with a small catfish. I recommend just keeping any real predators out of the tank, or at least those that are known piscivores.

The basic guidelines for a fish not suitable to keep with guppies are as follows:

  • Anything longer than 4 ½”
  • Any known piscivores over 2”
  • Any ambush predator
  • Most oddball fish (ie: Bichir, Black Ghost Knife, Eels)

This excludes a lot of really cool fish, but community tanks are always a compromise. Guppies will do well with any peaceful fish that can’t eat them. If you want the population to grow inside of your tank you’ll need to take care to only place them with small, peaceful fish like the ones on the first list.

Breeding Guppy

Breeding guppies is simple: stick them in the tank, add food, and wait.

These livebearers can produce two generations per year. They grow swiftly to sexual maturity and they’re easy to sex. All of this makes them a perfect fish for new breeders, as it avoids many of the challenges you’ll face with other species.

Guppies are known cannibals and eat their own fry. You can usually maintain a relatively stable population in the tank by adding enough plants and hiding places for the fry, but some will still be eaten.

Instead, you may want to set up a breeding tank. This also makes it easier to line breed guppy for special characteristics.

Breeding Tanks

A breeding tank for guppy is simple to set up. First, you want to cycle a tank that’s 10-20 gallons and add a few handfuls of java moss. A bare bottom is fine for this tank, the fry won’t be in there long.

You’ll also want a hatchery box of some kind. While I prefer the plastic models, net boxes also work. The important thing is that the fry can hide somewhere after they’ve been bred. I remove the parents from the breeder box once the whole litter is born and put them back in the main tank.

This is a simple setup and one that’s virtually identical to how professional breeders breed their show fish.

Sexing Guppies

Females are almost an inch longer than males and have less vivid coloration.

Sexing guppies is easy, but you also need to understand their mating strategy. Females will breed with multiple male guppies, and the strongest sperm will be the one that fertilizes her eggs.

I recommend a 3 to 2 male to female ratio when breeding. You can place the ones you want to breed in your breeding tank’s cage and allow them to have babies. Once the fry are all out of the female you can place her back in the main tank.

While they’ll still breed in the main tank, few offspring will make it to adulthood with a school of full-grown guppies and other fish in the mix.

Inbreeding Depression

Guppies are prone to inbreeding depression, especially when you have generations of the same animals mating in an uncontrolled manner.

That means the regular introduction of unrelated guppies is crucial. Every four to six generations you should introduce an unrelated animal to help keep the genetics of your guppies strong.

If you don’t, you’ll find that the new guppies are less hardy, less colorful, and may even have serious conditions that prevent them from surviving. The chances of this happening go up the longer you keep inbreeding the line.

Linebreeding Fancy Guppies

Before we get into this, I should note that you’ll probably need at least three tanks and a total of 80 gallons or more to line breed successfully. It requires a lot of room, planning, and a good understanding of basic genetics to succeed.

On the other hand, guppies are a prime candidate for line breeding. Linebreeding is done to ensure that a trait remains in the fish and possibly improves it.

It’s the reason we have such a wide variety of colors and patterns available. It turns out that in the wild guppy females prefer brightly colored males, but the really pretty ones get eaten due to sticking out. In a safe environment like a home aquarium these fish thrive and quickly began breeding into multiple colors and fin shapes.

One strategy to avoid inbreeding depression is to maintain two separate bloodlines in your fish and then cross-breed them every four generations or so. This helps create a strong genetic line but has to be carefully maintained to avoid inbreeding problems.

You can also out-cross your fish by purchasing another line of guppies.

While a bit of a pain, this is a necessary part of line breeding to keep fish healthy. Too much inbreeding will result in deformed fish with shorter lifespans, which isn’t good for anyone involved.

The actual breeding part is easy: place fish of opposite sexes that have a trait you wish to encourage and let them go through their courtship ritual. Once the female is pregnant you can place the males back in the main tank.

Fish can be chosen for color, fin shape, patterns, or any combination of the three. This can be a shot in the dark, but a good understanding of Mendelian genetics will help you along the way. 

Linebreeding and outcrossing need to be done carefully for success… and that can mean a lot of keeping track of where each fish is and what they bring to the table. More than one guppy tank is recommended for serious breeders, especially if you want to cross bloodlines without having to purchase more fish.

Recordkeeping, either on paper or in a digital format, is a requirement for successful line breeding. There are a lot of systems used, just find something that works for you. 

If you intend to get into breeding show guppies, instead of just interesting aquarium specimens, I recommend finding the closest club available to you.

The International Fancy Guppy Association keeps a list of sanctioned clubs. These clubs will have real experts in breeding, access to amazing bloodlines, and are generally helpful with breeding and care.

Linebreeding guppy requires time, space, and equipment but it’s one of the most rewarding parts of keeping guppies.

The Jewels of the Aquarium

Guppy care is as hard as you make it. There’s a big difference between keeping a school in a community tank and getting heavily into line breeding. Their specific oddity makes them an amazing fish that beginners can easily care for, while still leaving room for more advanced aquarists to find a challenge.

They’re a staple fish for a reason, and their hundreds of generations in captivity provide us with a myriad of tiny, jeweled fish suitable for almost any aquarium.