Guppy Care Sheet

Evan Baldonado

By Evan Baldonado
(Founder of AquariumKids)

The Guppy (Poecilia reticulata) is a hardy and stunning variety of fish. Spread throughout the world in an attempt to control mosquitos, they are now one of the most common fish in the freshwater aquaria hobby.

What you will need:


Despite their small size, Guppies are extremely active fish. Because of this, they require an absolute minimum of a 4 gallon enclosure. However, it is recommended to house them in at least a 10 gallon tank to help provide the best environment for them to live.


Guppies belong with a group of themselves, consisting of at least three individuals and at least 66% females if it is a group containing both sexes. Guppies in general are peaceful tropical community fish. They should not be housed with any aggressive species that could potentially nip their delicate fins (especially prevalent in some fancy Guppy varieties).


Most guppies are quite hardy. This means that, if you make a small mistake in the acclimation process, your Guppies will most likely be fine. However, do not take this as an invitation to go out and dump your new Guppies directly into your tank. Like all living creatures, maximum care and respect should be used when interacting with Guppies. To acclimate Guppies from their plastic bag from the store in the least stressful way, use the Drip-Acclimation method. Basically, you need to get them used to the new water parameters by slowly adjusting them. Open up their bag that they came in and gently empty the fish and water into a clean bin or large cup, making sure that the water level is high enough for them to swim. If your bag does not contain enough water to fit your fish into a bin or cup, simply open up their bag from the top.

Feeding Time

Guppies generally spend the majority of their time near the top of the tank. Because of this, small, floating pellets and watered-down flakes, are great choices for feeding them as they will allow for them to obtain the required food. However, most Guppies will also venture lower down into their tank, either for the sake of exploration or to find food. The most important thing is to make sure that your Guppies are getting adequate amounts of food, so experiment with different food types in order to identify which one(s) are the best fit for you and your Guppies.

Nitrogen Cycle

As many of you parents (and older kids) may have learned in school, the Nitrogen Cycle is the process by which the element nitrogen moves throughout our world. However, in the context of aquaria, the term "Nitrogen Cycle" generally only refers to part of the full Nitrogen Cycle which you may have learned about. It's pretty simple -- the aquaria Nitrogen Cycle covers the parts of the full Nitrogen Cycle that occur in aquaria. When fish, or any other tank inhabitant consumes food, they are consuming Nitrogen. Nitrogen is added to the aquarium (an enclosed system) through the addition of food, animals, plants and other biological material. When this material decays, it turns into a compound known as Ammonia (NH3). Special bacteria convert Ammonia into Nitrite and then some more convert that Nitrite into Nitrate. Both Ammonia and Nitrite are extremely toxic to all of your tank's inhabitants and can kill them if allowed to accumulate. When testing these two parameters, they should both display as under 0.5 ppm (parts per million), preferably as close to 0 ppm as possible. Nitrate is also toxic, but less so than its other Nitrogen cousins, and should be kept under 25 ppm. All of these can be removed from your tank via water changes (read below) and certain filters (sorry, you still have to perform water changes even if you have these). Some nitrate can also be absorbed by plants as they grow.

The aforementioned bacteria who are responsible for converting ammonia into nitrite and nitrite into nitrate aren't present in high enough levels to be effective when you first start up your tank. The process of building up these bacteria colonies to satisfactory levels is called "cycling." Cycling can be speed up by "seeding" your filter with filter material from an already-established aquarium. Cycling can eiter be done "fish-in" or "fishless." Though it is possible to do it either way, I would highly recommend doing it "fishless" in order to minimize fish stress. However, if you already have your fish and can't return them, there is no need to worry: you can cycle "fish-in," you just have to be extra careful and perform extra water changes and regular water testing. To cycle "fishless," you have to seed your aquarium with a source of ammonia to provide the bacteria with a food source for them to establish. Testing parameters weekly, you will be able to determine that your tank is ready for fish when ammonia and nitrite levels are zero and nitrate levels have risen.

Water Changes

As mentioned before, it is necessary to perform water changes to ensure your Guppies' well-being. While a common misconception is that you must remove all water from your fish tank to do a water change, this is actually not true. During a water change, you should only remove around 50% of the water to ensure that there are not any drastic parameter changes that could harm your fish. To remove water, either purchase a siphon or scoop it out using cups, bins, or buckets. Then, replace the water you just removed with dechlorinated tap water (try SeaChem Prime for a good, quality dechlorinator) of the same temperature, being careful not to disturb your fish too much as you add it in.

Water Parameters

While wild guppies generally prefer a pH between 7 and 8.5 and a temperature of 72-78F, commercially-bred Guppies are much more tolerant to a wide range of pH levels (6-9) and temperatures (70-82). It is most important to make sure that parameters do not undergo major fluctuations because these are more harmful to Guppies than

Decorations & Equipment

As mentioned before, Guppies come in countless varieties. Some are much more compact and nimble, easily managing to manuever themselves throughout the tank. However, some Guppies such as the Lyretail Guppy have long, flowing fins. When choosing decorations, be wary of this fact and avoid anything with sharp edges to help prevent your Guppies from injuring themselves.

Extra Notes

Thanks for reading this short care sheet on Guppies (published 1/1/16)! For more information, please browse around! Feel free to contact me at evanb [at] aquariumkids [dot] com with any questions.

Evan Baldonado
Image credit: "Guppy1trasp.png" by D3LL (CC BY-SA 3.0)