Are you considering adding some cute and colorful guppies to your aquarium collection? Then, let me tell you that these small and easy to care fish, will be a brilliant addition to your 20 gallon aquarium.
Guppies come in a wide variety of colors and patterns, making them a stunning addition to your tank. Because of their vibrant and stunning color they are called “rainbow fish”.
You might be wondering just how many of these little fishies you can comfortably fit into a 20-gallon tank. There are 2 important factors to consider when determining this: free swimming space and effective volume.
These 2 easy methods will help you find the correct stocking density in your 20-gallon guppy tank.
CONTENTS
- How Many Guppies Can Be Kept in a 20 Gallon Tank?
- The Free Swimming Space Method
- How Many Male and Female Guppies in A 20 Gallon Tank?
- The Effective Volume of Water in a 20 Gallon Tank
- Benefits of Having a 20-Gallon Guppy Tank
- Setting Up a 20-Gallon Guppy Tank: A Step-by-Step Guide
- People Also Ask
- FAQ
How Many Guppies Can Be Kept in a 20 Gallon Tank?
In a 20 gallon tank, you can keep 16 to 20 male guppies in a male only tank or 7 to 9 female guppies in a female only tank. Another option is to keep 4 male and 8 female guppies, if you want to keep both the male and female guppies in the same tank.
Keep reading, to learn, 2 very easy methods to determine the correct stocking density.
The Free Swimming Space Method
Overcrowding the tank can result in serious health problems for your guppies, such as trauma, low immunity, and diseases. In addition, this can lead to water pollution, rise in nitrates and building up of toxins which can prove lethal to your guppies.
To prevent these issues, it’s important to adopt the best stocking practices by understanding the necessary free swimming space to keep your guppies healthy.
To determine the free-swimming space for your fish, you’ll need to know 3 key factors:
- Gender and the average adult body length of the fish.
- Temperament of the fish
- Size of the tank (which in this case is 20 gallons).
The gender of the guppies plays an important factor in determining the average body length of the fish. Male guppies are smaller than the female ones.
The average male guppy fish measures 1 inch in body length (excluding the tail fin), while the average female is 2.2 inches in length. It’s important to note that these are average body lengths, not maximum lengths.
In terms of temperament, guppies are known to be social and non-aggressive fish. For a peaceful and social pet fish like guppies, the recommended free-swimming space is 1 inch of body length per gallon of water.
However, for more aggressive fish, the ideal free-swimming space is 1 inch of body length of fish per 2 gallons of water.
Therefore, if you are planning to create a male guppy-only tank, this is how you calculate.
20 (Volume in gallon) /1 (Length of fish in inch) = 20 (Number of fish)
You can easily accommodate up to 20 male guppies in your 20 gallon tank.
Since the female average body length is 2.2 inches, the free swimming space for a female guppy only tank will be:
20 (Volume in gallon) /2.2 (Length of fish in inch) = 9 (Number of fish)
You can easily accommodate up to 9 female guppies in your 20 gallon tank.
Now, what if you want to keep both males and females?
In this following section we will discuss that in detail.
How Many Male and Female Guppies in A 20 Gallon Tank?
You can keep 4 male guppies with 8 female guppies in your 20-gallon tank comfortably.
It’s important to avoid having more male guppies than females because guppies are prolific breeders. They reach maturity in just 3 months and constantly attempt to breed.
Male guppies will relentlessly chase the female ones to mate. Thus, it’s better to keep a ratio of 1 male guppy to 2 or 3 female guppies.
By following this ratio, you can soon have a brood of up to 40 guppy fries in your 20-gallon tank.
Now that you know the “free swimming space” method, let’s discuss the “effective volume method” as well.
Keep reading.
The Effective Volume of Water in a 20 Gallon Tank
Your guppies are not the only ones that take up space in your aquarium.
In addition to your fish, any decorations, aquarium plants, and filters that you have also take up space and can reduce the effective volume of water in your 20-gallon tank.
Assuming that the decorations, filter, and aquarium plants take up to 5 gallon of space, then the effective volume of your 20-gallon tank would be reduced to 15 gallons of water.
This means that the recommended number of male guppies you can keep in your tank would also be reduced to 15, since, only 15 gallons of water is left in the tank, for them to swim.
This will also reduce the number of female guppies in this scenario, from 9 to 7.
Ensure that your aquarium is not overcrowded, and that your guppies have enough room to swim and explore. This will help keep your guppies healthy in the long run.
Providing plants, Decoration and Hiding Spots
In an aquarium, plants, rocks, and decorations can take up a lot of free space. However, guppies enjoy having hiding spots, especially when they are young.
In a 20 gallon breeder tank where the fry stay with their parents, there is a risk that the parents may eat their own offspring as they may not recognize them.
Provide guppy grass (Najas Guadalupensis), water sprite, or other similar plants as these plants provide excellent hiding spots for the guppy fry. With enough hiding spots, the fry have a greater chance of survival as they won’t be spotted easily by their parents, who may try to eat them.
Setting Up a 20-Gallon Guppy Tank: A Step-by-Step Guide
Preparing to Set Up Your Tank
Choose a suitable location for your tank. Ensure that it’s not exposed to direct sunlight, as this can cause algae growth and affect water temperature.
If you live in a cold place you can absolutely keep your guppies aquarium near the window, where the sunlight is shining. In hot countries like India you should avoid direct exposure to sunlight.
Now it’s time to gather all the necessary equipment, including the tank, filter, heater, substrate, decorations, and plants.
Rinse the tank with warm water and dry it thoroughly before proceeding to set it up. Also, wash the rocks, decorations like driftwood, and substrate before moving any further.
Setting Up the Tank
Add the substrate to the tank. It should be about 2-3 inches deep and evenly spread across the bottom of the tank.
Fill the tank with water, leaving some space at the top for decorations and equipment.
Install the filter, and a heater of 75 watt or 100 watt according to your requirement or climatic condition. Also add a thermometer to your tank to constantly monitor the water temperature.
Adjust the temperature to around 75-82°F (23.88-27.77°C) as this is the optimal temperature range for guppies.
Add decorations and plants to the tank. Make sure to leave enough space for the fish to swim around and hide.
Allow the tank to cycle for at least 24 hours before adding any fish. This will establish a healthy bacterial colony that will help break down waste.
Adding Guppies to Your Tank
Choose healthy guppies from a reputable source.
Acclimate your guppies to the new environment by floating the bag in the tank for about 15 minutes to equalize the water temperature. Gradually add small amounts of water from the tank to the bag every five minutes to allow the fish to adjust to the new water chemistry.
Release the guppies into the tank, making sure not to pour the water from the bag into the tank, as this can introduce harmful chemicals and bacteria.
Feed your guppies a balanced diet of high-quality flakes, pellets, brine shrimp and blood-worm once or twice a day.
Maintaining Your Tank
Test the water quality regularly using a test kit to ensure optimal levels of pH, ammonia, nitrite, and nitrate.
Perform regular water changes of about (25- 30)% of the tank volume every week to remove excess waste and maintain water quality.
Clean the tank and equipment regularly to prevent the build-up of harmful bacteria and algae.
Observe your guppies daily to ensure they’re healthy and active. If you notice any signs of illness or stress, take action immediately.
Benefits of Having a 20-Gallon Guppy Tank
A 20-gallon aquarium is a great option for keeping guppies. It’s large enough to provide ample space for the fish to swim around, and small enough to fit comfortably in most homes.
Guppies can move freely and explore the entire aquarium, unlike larger tanks where they may stay near the top of the aquarium mostly.
Economical Benefits of a 20-Gallon Tank
20 gallon tanks are very common and easily available. Most 20-gallon tank comes with a starter kit and you can find lights, lids and other aquarium accessories inside the kit itself. This drives the cost low and is budget friendly.
Your filters are relatively small and you don’t have a huge upfront cost. A 20-gallon tank weighs around 200 pounds (90.71 kg) including water and the substrate, and you may not need an aquarium stand for it.
If you have a sturdy piece of furniture (table or desk) that can hold around 200 pounds of weight, then it should be okay.
Ease of Maintenance
Guppies are hardy fish and can tolerate initial mistakes that beginner fish keepers may make. A 20-gallon tank is an ideal choice for beginners, as there is less room for errors.
In smaller, 5-gallon guppy tanks and 10-gallon guppy tanks, though they are great for beginners, you don’t get the stability, as compared to the 20-gallon tank.
Water parameters will not fluctuate in a 20-gallon tank as compared to smaller tanks, and guppies are going to be healthier in the long run.
People Also Ask
Here’s a quick look at, some of the common question asked related to the tank mates of guppies.
How Many Mollies and Guppies in a 20 Gallon Tank?
There is no one answer fits all, for this question.
Mollies come in a variety of sizes, ranging from small Dwarf Mollies to larger Sailfin Mollies. This can have a significant impact on how many fish you can keep in a 20 gallon tank, as larger fish require more swimming space and produce more waste.
Dwarf mollies are the smallest variety, measuring in at just 2 inches. These fish are great for smaller tanks, and you can keep up to 4 dwarf mollies with 6-8 guppies in a 20 gallon tank. However, keep in mind that adding too many fish can lead to overstocking and potentially harmful water conditions.
Common mollies and black mollies are slightly larger, measuring in at around 3 inches.
For these fish, you can keep up to 3 mollies with 5-6 guppies in a 20 gallon tank. Again, it’s important to avoid overstocking, as this can lead to poor water quality and unhealthy fish.
Some larger variety of mollies like the Harlequin Sailfin molly or Yucatan Molly can measure up to 6-7 inches in length.
Due to their size, I recommended that you only keep 2 of these fish in a 20 gallon tank, along with 5-6 guppies. These fish require more swimming space, and adding too many can lead to overcrowding and stress.
NOTE: Mollies are fin nippers and might be tempted to bite the fins of your guppies. To prevent this, provide plenty of hiding places and keep your guppies in a planted tank, where they can feel safe.
How Many Guppies and Neon Tetras in a 20 Gallon Tank?
In a 20 gallon tank, you can keep up to 10 guppies and 6 neon tetras. However, it’s important to note that neon tetras are known to be fin nippers and might bite the fins of your guppies.
To prevent this, provide plenty of hiding places and keep your guppies in a planted tank where they can feel safe.
FAQ
You can keep up to 16-20 male guppies in a 20 gallon tank provided you have minimal decorations and the substrate and filter don’t take away much of the effective volume of the tank.
You can keep 7 to 9 female guppies in a female only 20-gallon tank.
You can have 10-12 fancy guppies in a 20-gallon tank. Don’t keep sharp pointed rocks as that can damage their elaborate flowy fins. Don’t keep any fin-nipper in your tank as the may bite their fins.
Conclusion
Adding guppies to your aquarium collection can be a great way to bring color and vibrancy to your tank. However, it’s important to consider the appropriate stocking density to prevent overcrowding and maintain a healthy environment for your fish.
The two easy methods discussed in this article, the free swimming space method and the effective volume method, can help you determine the right number of guppies to keep in your 20-gallon tank.
By following the suggested ratios, you can keep up to 20 male or 9 female guppies in a single-sex tank, or 4 male and 8 female guppies in a mixed tank. Providing plants, rocks, and hiding spots can also help create a healthy and stimulating environment for your guppies.
Image Credit:
Featured Image – Fins [day 140] by gerlos | Source- Flickr | License: CC BY-ND 2.0
