How Many Guppies in a 20 Gallon Tank? (Must-Read)

Are you considering putting guppies in your 20-gallon tank? That’s a great idea! Guppies are an excellent addition to any home aquarium — they’re peaceful, colorful, and full of character. But when it comes to numbers, how Many Guppies in a 20 Gallon Tank should you stock?

The answer might surprise you! This blog post will review the critical aspects of determining how many guppies can be in a 20 gallon tank.

First, how significant are the guppies themselves? Guppy sizes can range from 1 to 3 inches, with the average size being around 1.5 to 2 inches long.

Determining how many guppy fish you can have in your aquarium takes a lot of work.

If you overfill it, the tank’s environment can quickly become toxic and put your fish’s health at risk.

can different types of guppies breed

You don’t want to make a mistake that wipes out your entire tank and all its inhabitants. Picking the wrong size tank or too many fish could cause significant damage or severe illness.

So, how many guppy in a 20 gallon tank? With our detailed guide on tank sizes, water conditions, and stocking levels – we’ll help you pick the correct number of guppies for your aquarium so they can thrive safely.

Read on for all the must-know details to ensure your new finned friends stay happy and healthy!

How Many Guppies in a 20 gallon Tank?

How many fish can you put in a 20-gallon tank? how many guppies in 20 gallon tank really depends on several factors, such as the fish’s size, activity level, and water parameters. 

You can generally have 2-3 guppies per gallon of water for guppies. That means you can comfortably stock 10-15 guppies in a 20-gall tank.

Different Types of Guppies School Together

However, it’s essential to remember that guppies can reproduce quickly, and the population can grow faster than expected. You should be prepared to add additional tanks or trade/sell your extra guppies if the population gets too large.

What Is the Rule for the Number of Guppies Fish Per Gallon?

How many guppies per gallon of water? In most instances, fish must be a foot per gallon. Adults are around 1 – 1 inch tall, meaning you have one Guppy for every quart of water. Keeping 2-3 guppies per gallon of water is often recommended.

Remembering that this is just a guideline and not a hard and fast rule is essential. Before stocking any tank with fish, it’s important to research the specific species you plan to keep. Fish species have different needs, and some require more space than others.

Do the Gender of the Guppies Matter?

Gender is essential in selecting the number of guppies for a tank. Male guppies tend

defend their territory against other males, so you should keep only male guppies or limit the number of males in a tank to one or two.

How Many Male Guppies Could You Put in a 20-Gallon Tank? Fish keepers without experience often mistakenly think guppies are identical and have nothing different. Most aquarium fish keepers can distinguish between males and female guppies.

Female guppies usually are bigger than male ones since female guppies generally have shorter and round bodies, while male guppies appear thinner and shorter in appearance. As previously stated, the average size for females of guppies is 1.5in. Males are 1.5in.

Male guppies appear brighter and more colorful than females, particularly in their gypsy tails and the size of their fins.

How To Calculate How Many Guppies Can Be in a 20-Gallon Tank?

How many guppy in a 20 gallon tank? It is a mistake to put all the guppies into a fish tank. Guppies need plenty of time to swim, and adding more fish may create various problems that will later be described. Another point is that the tanks will not get full because of the equipment.

It would help to choose what guppies you would add to an aquarium carefully. – a few more. The primary method for calculating the number of guppies per inch in your guppies tank is 1 gallon of water per Guppy per inch. It requires two gallons of water. That means, for a 20-gallon tank, you can add up to 10 guppies.

What Fish Can Live with Guppy Fish in a 20-gallon Tank?

What Are The Best Tankmates for Guppies in 20-gallon Tanks? Guppies can easily be kept with smaller fish like Corydoras, Neon tetras, Harlequin Rasboras, and Otocinclus Catfish.

These fish are compatible with guppies and require similar water parameters. Keeping compatible tank mates together can also help create a more enjoyable, lively environment.

Avoiding aggressive fish with guppies is essential, as they can be easily intimidated and stressed. You should also avoid keeping larger fish as they can see guppies as prey or competition for food.

Other Tankmates we can keep with Guppy in 20 Gallon Tank:

An owner should take care of numerous aspects of their guppy tank before adding others to the guppy tanks. Besides the fish listed above, you can keep tiny snails like Nerite Snail and Malaysian Trumpet Snail in a guppy fish tank. 

These snails are peaceful and algae eaters, so they can help keep the tank water clean by eating uneaten food and algae. Shrimps like the Red Cherry, Ghost, and Amano are also good tankmates as they are peaceful and can thrive in the same tank water conditions as guppies.

How to Setup the Ideal 20-Gallon Guppy Tank?

The installation of guppy tanks is relatively simple if you follow specific fundamental rules. This way: Here are some tips to help you out:

Choose the ideal tank.

The 20-gallon tanks should be used for this purpose as they provide enough space for the fish to swim and grow.

Provide a Powerful Quality Filter and air pump.

The internal or external filter must always be used when you’re the beginner guppy keeper. Use water filters and air pumps that take up 100 liters of aquarium water daily.

Add substrate

Once your filter is installed, you can add gravel. The substrate is available in the pet store. Add about three inches of fish gravel to the tank. Only use gravel that comes from your backyard. It can cause bacteria to invade your water tanks. Also, ensure that the gravels have compatibility with the living plants.

Add more live plants to your tank.

It is recommended to keep your aquarium in an aquarium. In my fish tank, live aquatic species look not so beautiful. They can also help me in a great way. Living aquatic plants maintain the water’s cleanliness as toxins from fish waste eat the water’s litter and are used in plants. What should we know when preparing for a new aquarium?

Add Water Heater Guppies

It would help if you had a temperature range between 75 and 85 degrees Fahrenheit, which can be achieved by adding a water heater.

Strike the recommended ratio.

Ensure the ratio between male and female guppies in the tank is 1:1; each male should have two female guppies. If there are more females than males, it can lead to harassment of females.

Feed the correct food quantity.

Give it two times daily in flakes of good flavor. It should include plenty of protein for growth.

How Do You Keep a Healthy Guppy Tank

You can keep guppies at home, and they are so cute! All water variables should always be checked, filtered, and treated to ensure a healthy environment for these animals.

Regular maintenance of the tank is required to keep it healthy. Clean your tank regularly, remove dirt and debris, and replace the water as needed. Monitor for any signs of illness or parasites and treat them accordingly.

Make sure to feed your guppies high-quality food with plenty of proteins and vegetables. Finally, provide lots of hiding places for them and ensure their tank is in a place where they can have regular light cycles.

You will have healthy guppy tanks for years with these tips and regular tank maintenance.

What Will Happen If I Add Too Many Guppies?

A little smaller than the guppies will make you feel you must add more than you wish to the aquarium. However, the overcrowded aquarium is not advisable, so it is essential to stick to this calculation. Adding more guppies in a fishing vessel could lead to several issues, including:

  • Stressful environment for the fish.
  • Increase in the spread of diseases and parasites.
  • Water parameters can be challenging to maintain.
  • Low oxygen levels in the tank due to overcrowding.
  • Lack of space for proper swimming and natural behaviors.

To avoid any of the above issues, it is essential to adhere to the recommended stocking levels and use caution when adding new fish.

Safe stocking levels differ depending on the size of the fish tank, the type of filtration system, and other fish environmental factors. It is always best to consult a veterinarian or an experienced fishkeeper before taking drastic steps.

Commonly Asked Questions about 20 Gallons Fish Tank (FAQ)

How Many Guppies and Neon Tetras in a 20-Gallon Tank?

Such a tank is a perfect size for small and medium-sized aquarium fish. If you are looking to stock your tank with guppies, it is recommended to have four guppies per 10 gallons of water. You should have at least six fish per 10 gallons for neon tetras.

How Many Guppies in a 20 Gallon Tank Female to Male Ratio?

When stocking a 20-gallon tank with guppies, you should aim for a 1:1 ratio of female to male. This means that for every male Guppy, you should have one female. This will reduce the chance of male guppies harassing the females.

How Many Guppies Should Be Kept Together?

A single male guppy can be kept in an aquarium with two or three female guppies. This ratio allows the male to spread its fins and display its colors without becoming too stressed while ensuring that the females aren’t overfertilized.

How Many Guppies in a 40-gallon Tank?

You can keep up to 40 adult Guppies in a 40-gallon tank if you provide adequate filtration, water changes, and aquatic plants. Having one adult Guppy per gallon of tank water at most is generally recommended.

How Many Tetras in a 20-Gallon Tank?

When stocking a 20-gallon tank, the recommended amount of tetras is 11 to 12. This allows each fish ample space and can provide impressive aquatic displays.

How Many Mollies and Guppies in a 20-Gallon Tank?

With a 20-gallon tank, you can have the perfect setup for breeding guppies and mollies. Guppy’s peaceful demeanor makes them an ideal companion to their active friend – Mollies! At a minimum, eight gups + 3 molls should comfortably inhabit your underwater kingdom but feel free to adjust this number according to specific larger Molly breeds’ needs.

How Many Guppies in a 30-Gallon Tank?

You can keep up to 30 adult guppies in a 30-gallon tank if you provide adequate filtration, water changes, and aquatic plants. One adult guppy per gallon of tank water is recommended at most, so the stocking limit for a 30-gallon tank is 30 guppies.


So, how many guppies in a 20 gallon tank will live peacefully? In conclusion, knowing how many guppies to put in a 20-gallon tank can be challenging. However, with the information in this post, you know that a 20-gallon tank can comfortably hold around 8 to 10 adult guppies. What’s more important than the quantity is the quality of care for your fish. Since guppies are particularly sensitive to their environment, keeping water parameters stable is essential as ensuring they have enough space and hiding places.

With proper care, there is no limit regarding how many happy, healthy guppies your 20-gallon tank can accommodate! If you found this blog post helpful, please remember to share it with others; after all, knowledge shared is knowledge gained!

You might also like

About Me

I am the founder of, a devoted wife and mother, and an avid fish enthusiast. My aim is to assist fellow fish lovers worldwide in understanding how to properly care for and breed their pet fish.

Recent Posts

Stay Updated

Get outdoor trends, data, new products, and tips delivered to your inbox.

error: Content is protected !!
Scroll to Top