Guppy Fish Tank Requirements – Everything Guppies Need

Guppies are adaptable and low-maintenance pets. However, that’s not to say that guppies can survive and thrive in just about any type of condition. You can’t just throw them in a glass bowl and call it a day. There are still water and tank requirements worth considering, although you have way more leeway than with other fish species.

If you aren’t sure how to set up the perfect guppy tank, keep reading! In this article, I’ll talk about exactly what guppies need to thrive and live long and happy lives. From the tank itself to the tech, to the miscellaneous tools, I’ve got you covered! Here’s exactly what you need to consider for the perfect guppy aquarium.

The Right Tank Size

Guppies are medium to small-sized fish. If your guppies weren’t bred for size, you can expect a mature male guppy to reach no more than 1.4 inches, while females will average 2.4 inches at most. However, despite their modest proportions, guppies need plenty of space to move around freely.

If you want to keep a large number of guppies, aquarium dimensions will be the first thing to consider. To get a better idea about how much space you’ll need, remember that each full-grown guppy should have at least 1-3 gallons of water worth of space for itself. So, for example, if you decide to keep 7 guppies, we’re talking about a tank up to 20 gallons.

Another good estimate you can use is the 1 gallon of water per 1 inch of fish. If the average guppy is around 2 inches long, then you’ll need 2 gallons of water for every guppy in the aquarium. That falls right in the middle of the 1-3 gallons estimate.

If you’re just starting out keeping guppies, I usually recommend a 10-gallon tank. This is enough space to keep 3-5 guppies, and this tank size is also appropriate for most aquarium equipment. Not to mention that it also doesn’t take up a lot of physical space, so you can place the aquarium on a desk or a small table.

These tips should make choosing the right tank size a lot easier. However, if you can buy an even larger aquarium, that’s even better. You can always add more guppies to a bigger aquarium, and the extra space will be a saving grace when your mature guppies start breeding.

Setting up a separate tank when the main aquarium gets overcrowded… Now that’s going to be more complicated. For example, it takes a couple of weeks to cycle a new tank. During this time, the new space is uninhabitable for your new guppies.

A Water Filter

The opinion is split when it comes to water filters. There are a lot of people, myself included, who believe that a water filter is important. However, you might have also seen people who claim they can safely keep guppies without a filter. So, who’s right here? Well, the truth is that you can safely keep fish in a filterless aquarium. I’ve even written about this in previous articles.

But I still believe it’s a better idea to invest in a water filter, especially if you’re new to the aquarium hobby. Not only does a water filter make maintenance easier, but you also get more leeway when setting up your aquarium. With a trusty water filter on hand, you won’t have to worry as much about finding the perfect substrate, cycling your aquarium perfectly, or keeping a lower number of guppies, for example.

While a water filter takes a bit of additional space and it might take away from the beautiful view, the benefits it brings you, especially as a beginner guppy keeper, are indispensable. Water filtration is all the more important for smaller size tanks, as water parameters are difficult to monitor and maintain when the water volume is low.

However, whether you have a smaller or larger-sized tank, a good filter will always come in handy. A filter takes care of waste and debris and keeps the water clean for longer. It also extends the time between water changes, and it allows you to keep more guppies in the same tank.

Perhaps most importantly, a water filter will help you maintain suitable water parameters without sudden fluctuations. Because filters take care of waste and prevent ammonia build-up, you won’t get dangerous drops in water pH that could harm your fish. The filter media also serves as a ground for good bacteria to build up, so you get extra biological filtration if your tank isn’t fully cycled yet.

Regarding the best type of filter, for a 10-gallon tank, I usually recommend hang-on-back filters. These are space-saving, affordable, and they do the job perfectly. You can find many great HOB filter options with adjustable flow and multiple types of filter media included for a good price.

Plants And Other Decorations

Plants are a great addition to any aquarium. They are visually pleasing, and they also have multiple perks. They support the nitrogen cycle by recycling harmful compounds, and they keep the water clean for longer. In a way, they are a type of biological filter.

They also prevent algae from growing. The more live plants, the less unwanted algae growth you’ll get. That’s because the plants will take up all the resources in the soil, starving the algae away. Live plants also double as a healthy snack for your guppies.

Depending on the type of plants in your aquarium, your fish could be getting a lot of vitamins and minerals each time they dig in and nibble. Dark green plants also contain several pigments like chlorophyll or beta carotene, which help your male guppies maintain their vibrant colors.

Last but not least, live plants are also good at reducing stress in fish because they make for good hiding spots. Decorations are also a good idea for any aquarium. Like live plants, decorations offer cover for smaller, weaker guppies or female fish.

You can add any aquatic plant, but I recommend choosing low-maintenance options to make your life easier. Some plants grow like weeds, and they’ll require frequent trimming. Other plants need lots of light exposure to grow and stay healthy.

The most difficult to manage are the plants that need fertilizers to grow because adding fertilizer can, in turn, impact water quality. The best live plant options would be ones that don’t require any fertilizers or frequent light exposure.

Whichever types of plants you choose, always remember to use a nutrient-rich soil type of substrate and make sure to sterilize your plants before introducing them to the aquarium. Plants are often contaminated, and taking some extra safety measures will help prevent your fish from contracting some harmful bacteria or parasites.

A Water Heater

You may already know that guppies are a tropical species. It means they’re naturally accustomed to warmer water, and they require higher water temperatures to thrive. Ideally, water temperatures for guppies shouldn’t fluctuate outside the range of 72-82°F.

Unless you live in a sunny, tropical country with high temperatures year-round, I’d say having a water heater is necessary. If room temperature ever drops below 68°F, a heater becomes mandatory. That’s because, for a smaller-sized tank, water fluctuations can happen fast, usually across a few minutes to hours.

Temperature fluctuations also apply to larger aquariums. It’s just that it would take longer. If you get fluctuations in temperature from season to season, or during the day and at nighttime, you can be sure that the temperature in your aquarium will drop below the minimum ideal level, no matter the water volume.

A water heater is the only way to maintain constant optimal water temperatures year-round. You’ll need a heater that’s powerful enough to warm up all the water in the aquarium. Most products on the market have the recommended aquarium size in the list of specifications.

However, if you can’t find any information, you can use the 5 watts per gallon of water volume rule. For aquarium sized 50 gallons and under, you’ll need about 5 watts per gallon to increase the water temperature 5-10°F above room temperature. In other words, a 50-watt heater is enough to increase the temperature in a 10-gallon tank by up to 10°F.

Artificial Lights

Aquarium lights aren’t a must-have, but they do add to the appearance of the aquarium. They really play up all the colors in the tank, and they help you see your guppies a lot better. The fish themselves don’t need artificial lights to thrive, especially if they get enough natural light exposure during the day.

However, if you keep your guppy tank away from windows, or if you plan to add some live plants, that’s a different story. Natural daylight might not be enough for the plants in the aquarium to thrive. Also, if you keep the aquarium in a dim-lit room, this might impact your guppies’ resting habits.

Artificial lights are an easy and effective way to solve both of these problems. Just remember to not let the aquarium lights on 24/7. Guppies regulate their activity, rest, and energy expenditure through outside cues such as light. If the lights are on all the time, your guppies will skip on important rest, which can harm their health.

Constant light exposure might also encourage excessive algae growth, which will be hard to deal with. I recommend setting up a running schedule for your artificial lights. The closer you can get to mimicking the natural day-night pattern, the better.

Additional Things for Aquarium Maintenance

We’ve gone through what your guppies need to thrive. But besides the perfect tank set-up, there are some extra things that you’ll need to keep it all running. These are some of the tools necessary to maintain the aquarium, to manage your guppies, and to meet all the required water parameters:

  • An air pump – This is a very important addition to any aquarium, as it helps to maintain optimal oxygen levels in the water. It works by creating water bubbles that travel up to the surface. As these bubbles break surface water tension, the oxygen can easily get into the water where it’s needed.
  • A bucket – You’ll need to perform weekly water changes to dilute or remove dirt and toxins. Since we’re talking about gallons worth of water being moved around, you’ll definitely want a bigger recipient to get things done quicker.
  • A fish net – Sometimes, you’ll need to fish things out of the aquarium. Maybe you want to change some decorations or you need to inspect some of your guppies. It’s not a good idea to do this bare-handed, for obvious reasons.
  • A gravel vacuum – The filter does a lot of the hard work keeping the aquarium clean, but you’ll still have to deal with some fish waste and food leftovers that sink to the bottom of the tank. A vacuum is the quickest way to clean the substrate when performing maintenance tasks.
  • A water testing kit – Maintaining the right water parameters is crucial if you want happy, healthy, long-lived fish. The problem is that you can’t tell the pH or toxin levels of the water just by looking at it. That’s where the water testing kit comes in handy. You’ll get precise measurements that’ll tell you exactly what you need to address.
  • A dechlorinator – Besides toxins, disinfectants like chlorine are another health hazard for your fish. You should never use chlorinated water in your aquarium. Not only could it kill your guppies, but it can also kill the good bacteria that build up in the aquarium after the nitrogen cycle. A dechlorinator will remove the harmful chlorine from tap water, making it aquarium and guppy-safe.
  • High-quality feed – This goes without saying, but feeding your guppies high-quality food will lead to optimal development and better health outcomes. Relying on cheap, low-quality food can lead to deficiencies, poor immunity, and various health problems.
  • A breeding box – If you keep a mixed tank of both male and female guppies, breeding is inevitable. If you plan to keep the guppy fry, you’ll have to separate the pregnant females while they give birth. It’s way easier to let female guppies give birth in a breeding box than trying to pick out the newborn fry from the main aquarium.

Remember that these are just some of the most common and important tools and accessories you might need. While this might seem like a long list, I guarantee you each of these will prove useful at the right moment.


Like any other fish species, guppies have a set of requirements for optimal health. At the very least, you’ll need to provide them with a roomy, well-filtered, well-heated aquarium. But artificial lights, live plants, and decorations bring additional benefits. The closer you can get to mimicking their natural habitat, the better.

There are also some additional tools you’ll need for aquarium maintenance. Weekly cleaning and water changes are still important, even if your aquarium is well-filtered. Last but not least, try to offer your guppies a nutritionally complete diet of high-quality food sources. If you follow these recommendations when setting up your tank and looking after your guppies, you should enjoy great results.

avatar Noah
I’m Noah, chief editor at VIVO Pets and the proud owner of a playful, energetic husky (Max). I’ve been a volunteer at Rex Animal Rescue for over 2 years. I love learning and writing about different animals that can be kept as pets. read more...

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