If you want to know what size tank do guppies need, then you are in the right place.
Guppies need at least a 5 gallon tank in which you can keep three guppies. If you want to keep more guppies, then you’ll need a larger tank. A good rule of thumb to follow while deciding on the tank size for guppies is 1 gallon per inch of fish.
The table below shows the standard tank sizes as well as the number of guppies that can be kept in them.
|Number of guppies
|5 gallon (19 litres)
|10 gallon (38 litres)
|15 gallon (57 litres)
|20 gallon (76 litres)
|30 gallon (114 litres)
|55 gallon (208 litres)
Table of Contents
What is the Minimum Tank Size for Guppies?
The minimum tank size for guppies is five gallons.
In a five-gallon tank, you can keep a trio of guppies. And the male-to-female ratio should be 1:2 i.e. 1 male and 2 females.
However, if you are new to fishkeeping or if you are a beginner, then a small five-gallon tank is not recommended to start with because it is difficult to maintain a small tank like a 5-gallon tank compared to a larger tank.
That’s why you will soon end up with a lot of guppies in a five-gallon tank. And at that point, you have to upgrade your tank to a larger tank.
That’s why instead of a five-gallon tank, you should start with a 10-gallon tank.
What Factors Affect the Tank Size of Guppies?
There are a few factors that can affect the choice of tank size for the guppies you want to keep.
The number of guppies you want to keep
The most important factor that can affect the tank size for guppies is the number of fish you want to keep in the tank.
When deciding on the tank size for guppies, a general rule of thumb to follow is one gallon per inch of fish.
On average, guppies grow up to 2 inches. So you will need two gallons for one gappy fish.
However, guppies are schooling fish which means that they like to be in a group.
So you should not keep only a single guppy fish in your aquarium.
What is the bare minimum number of guppies I should keep in my aquarium?
You should keep at least three guppies in your aquarium. And out of the three guppies, two should be females and one should be male.
Because male guppies can be aggressive, the 2:1 female-male ratio is critical. And if there are more males in the tank than females, the females will be stressed, which can lead to diseases and even death.
Artificial Aquarium Decorations
One thing that is frequently overlooked when it comes to tank size for guppies or any fish is that when you choose a tank size, say a 10-gallon tank, it will not actually hold 10 gallons of water.
This is because in the aquarium you will need to put other things like substrate, artificial decorations, and equipment, which can take up space.
So ultimately, the fish tank will not hold water up to its total capacity.
Keeping this in mind, if you intend to keep a large number of artificial aquarium decorations in your tank, this can take up a lot of space.
As a result, your fish tank will eventually hold less water than its full capacity.
You should keep this in mind when selecting an aquarium for your guppies.
For example, as previously stated, the general rule for tank size for guppies is one gallon per inch of fish.
So, if you want to keep five guppies, and guppies grow to be about two inches long on average, you might think a 10-gallon tank will suffice.
However, if you intend to keep a large number of decorations in your tank, a 15-gallon tank is preferable to a 10-gallon tank for keeping five guppies.
Because the artificial decorations will take up a lot of space in your tank, so your tank’s actual water-holding capacity will be lower.
Live Aquarium Plants
Whether you are going to keep live aquarium plants in your aquarium or not will also come into play when deciding how many guppies you should have in the aquarium.
The thing is, live aquarium plants can absorb harmful toxins like ammonia, nitrite, and nitrate from your aquarium, which are produced by the fish waste in the aquarium.
Besides, live aquarium plants also help to keep your fish tank well-oxygenated by releasing oxygen into the tank.
So, if you keep a lot of live aquarium plants in your guppy tank, you will be able to keep more guppies than if you did not keep a lot of live aquarium plants.
This is because, as previously stated, live plants absorb harmful toxins from the water, which helps to dilute the toxins in the water, allowing you to keep more fish for the amount of water in your aquarium.
Submersible Aquarium Equipment
Just like aquarium decorations, submersible aquarium equipment can also occupy a lot of space in your aquarium. So it will lower the actual water-holding capacity of the tank.
For example, if you put an internal filter or a sponge filter in your aquarium, it will take up more space than if you used a hang-on-the-back filter or canister filter that sits outside of the tank and does not take up space inside the aquarium, allowing you to keep more fish in the tank.
Another common piece of equipment that you may need to put in your aquarium is an air pump, which generally sits inside your aquarium, occupying some space.
Overall, when deciding on tank size for guppies, you should also consider the type of equipment you intend to keep in your tank.
How to Decide How Many Guppies to Keep in Your Tank?
The number of guppies you should keep in your aquarium depends on the actual water-holding capacity of your fish tank.
For example, let’s say you want to keep 5 guppies in a 10-gallon tank. Then the actual water holding capacity of the 10 gallon tank will not be 10 gallons, but instead, it may be 8 or 9 gallons.
This is because you will need to add other things to your aquarium.
For example, you will need to add substrate to your fish tank. And you will need to add essential equipment like a filter and an air pump to your tank, which will occupy some space in your fish tank.
So, to accurately know how many guppies you should keep in your fish tank, you should first set up your fish tank with all the things you want to have in it.
Once everything is in place, i.e. you have added substrate to the tank, set up all of the equipment in the tank, and added all of the aquarium decorations that you want in the tank, you should add water to the tank and measure how much water you are adding.
And then, by using the general rule of thumb of one gallon per inch of the fish, you should decide how many guppies you should keep in your aquarium.
On average, guppies grow up to 2 inches. So you will need two gallons of water per guppy fish.
Let’s understand this with an example.
Let’s say you have set up a 10-gallon tank in which you have added substrate, an internal aquarium filter, an air pump, a water heater, and some aquarium decorations.
You’ve now added water to the tank, and you’ve ended up with only 8 gallons of water in a 10 gallon tank.
So in this case, by following the rule of one gallon per inch of the fish, and as guppies grow on average two inches long, you should keep four guppies in the tank.
How to Know if You’ve Chosen the Wrong Tank Size for Guppies?
In general, choosing a larger tank than is necessary will not cause any problems; in fact, choosing a larger tank is actually beneficial and recommended, especially if you are a beginner.
This is because larger tanks are easier to maintain than smaller tanks because water parameters in larger tanks do not fluctuate as quickly as they do in smaller tanks. And toxins such as ammonia, nitrite, and nitrates do not build up as quickly in larger tanks.
So, how do you know if you’ve chosen a smaller tank for your guppies? In other words, how do you know if you’re keeping more guppies or overstocking guppies in your tank?
There are several signs that suggest that your fish tank is overstocked.
Guppies will get very aggressive if you keep them in a relatively smaller tank.
Guppies will now chase each other regardless of the size of the aquarium. But when they start biting each other’s fins, it’s a sure sign that you’re keeping them in a smaller tank.
High Ammonia or Nitrate Built Up
When you keep more guppies in a smaller tank, ammonia builds up quickly, and this is a clear indication that your aquarium is overstocked.
If your fish tank is cycled then, in that case, you may notice a lot of nitrates building up quickly in your aquarium if you overstocked it.
In general, less than 40 PPM nitrates should be built up within a week.
If the nitrate build-up is far more than 40 PPM within a week, then it is a sign that you have overstocked your aquarium.
If you notice your fish moving quickly all day in your aquarium and gasping for air near the surface, this is a sign that they are very stressed.
And this could be because you overstocked your aquarium.
Fish Frequently Suffering From Diseases
Overstocking your aquarium, as previously stated, will stress out the fish and cause high toxins like ammonia and nitrate to build up in your aquarium, all of which can lead to diseases in your guppies.
So, if your guppies are frequently getting sick, it’s possible that you’ve overstocked your aquarium.
Shorter lifespan of the fish
Your guppies may have a shorter lifespan because you keep them in a smaller tank.
Again, keeping fish in a smaller tank will stress the fish and cause toxins to build up quickly in the tank, potentially shortening the fish’s life.
What Size Tank Do I Need for 2 Guppies?
For two guppies, you will need at least a five-gallon tank. It is recommended to keep at least a trio of guppies in an aquarium with a 2:1 female-male ratio.
However, if you want to keep only two guppies in the tank, then you should keep either both male or female guppies.
What Size Tank Do I Need for 6 Guppies?
The ideal tank size for 6 guppies is 15 gallon tank. However, if you have some experience in the fishkeeping hobby and you can maintain the nitrate level below 40 PPM, then you could keep six guppies in a 10 gallon tank.
What Size Tank Do I Need for 5 Guppies?
The ideal tank size for 5 guppies is 10 gallons. Out of the five guppies, three should be females and two should be males.
Can I Put 3 Guppies in a 5 Gallon Tank?
You can keep three guppies in a 5 gallon tank. Out of the three guppies, two guppies should be females and one should be male.
Can You Put 2 Guppies in a 1 Gallon Tank?
You should not put two guppies in a 1 gallon tank. A 1 gallon tank is not big enough for two guppies. For two guppies, you’ll need at least a 5 gallon tank.
How Many Guppies Can You Put in a 1.5-gallon Tank?
You should not put guppies in 1.5 gallon tank because it’s too small for them. The minimum tank size for guppies is 5 gallon in which you can keep three guppies.
Can You Have Just Two Guppies?
You could keep only two guppies in your fish tank. Just make sure to choose at least a 5 gallon tank for them and either keep only females or males together.
How Many Guppies Can I Put in a 10 Gallon Tank?
In a 10 gallon tank, you can keep five guppies. You could keep more than 5 guppies if you have some experience in the fishkeeping hobby and you know how to keep the nitrate levels below 40 PPM.
Can You Keep 3 Male Guppies Together?
You can keep 3 male guppies together. You should choose at least a 5 gallon tank for them (the bigger the better)
Here is an article that will help you to handle aggression among males.
Can I Keep 3 Female Guppies Together?
You can easily keep 3 female guppies together. Just make sure to keep them in at least a 5 gallon tank.
Can a Guppy Live in a 1 Gallon Bowl?
Guppy cannot live in 1 gallon bowl. As guppies are schooling fish, you should keep them in at least a group of 3 in at least a 5 gallon tank.
How Many Guppies in a 20 Gallon Tank?
You can keep 10 guppies in a 20 gallon tank. You could keep more than 10 guppies in a 20 gallon tank if you have some experience in the fishkeeping hobby and know how to keep the nitrate levels below 40 ppm.
How Many Guppies in a 5 Gallon Tank?
You should keep 3 guppies in a 5 gallon tank. And out of the 3 guppies, two guppies should be females and one should be male.
How Many Guppies in a 10 Gallon Tank?
You can keep five guppies in a 10 gallon tank. You could keep more than 5 guppies in a 10 gallon tank (up to 6 to 7 guppies) if you have some experience in the hobby and you know how to keep the toxins such as ammonia, nitrate, and nitrates low in the aquarium.
How Many Guppies Should Be Kept Together?
Guppies are schooling fish, so you should keep at least 3 guppies together in a 5 gallon tank.
And out of the 3 guppies, two guppies should be females and one should be male.
Overall, the ideal tank size for guppies is really dependent on the number of guppies you want to keep in your aquarium. Guppies are schooling fish, so you should keep at least three guppies. And the minimum tank size for three guppies is 5 gallon.
If you want to keep more guppies, then you will need a larger tank.
A general rule of thumb to follow when it comes to tank size for guppies is one gallon per inch of fish. And guppies generally grow up to two inches, so you’ll need 2 gallons of water in the tank for 1 guppy.
Hopefully, the tips I have mentioned about deciding how many guppies you should keep in your aquarium are helpful for you.