How Many Guppies In A 5 Gallon Tank? | Aquascape Addiction

How Many Guppies In A 5 Gallon Tank?

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We cover how many guppies you should have in a 5 gallon tank, how big they grow and some helpful care tips so you can look after them the right way.

How Many Guppies In A 5 Gallon Tank?

Guppies are cool little fish and they can come in many different color variations. They tend to be pretty hardy fish, so keeping them is not too hard. Therefore, they make a pretty good type of fish for beginners like kids or just first time fish owners in general.

They are resilient, not hard to feed, they can handle varying water conditions, and they are not too large either. You probably need to know how to house guppies, especially when it comes to keeping them in a tank. Let’s talk about how big guppies grow to, how much tank space they need, and how many guppies in a 5 gallon tank are ideal.

How Big Do Guppies Grow?

Generally speaking, no guppy is going to grow to be longer than 2 inches in length. Like we said, these are relatively small fish, which does bring a certain level of convenience for anyone who owns them.

Although female guppies will usually grow to around 2 inches long (this is how long it takes), males tend to be a little shorter and will usually only grow to around 1.5 inches in length. These guys might be small, but their appearance, especially their vastly different colors, has always been a big selling point for these little fish.

How Much Room Does A Guppy Need?

If you just want to keep a single guppy, or just a couple of them, there is a rule that you need to follow. This general rule of thumb is that you will need 1 gallon of aquarium space for each and every single inch of fish.

How Many Guppies Per Gallon?

Therefore, a 2 inch guppy will require about 2 gallons of water. If you have 2 males that are 1.5 inches and 2 females that are 2 inches long, you will need a 7 gallon aquarium, 1 gallon for each inch of fish.

Beginners should aim to keep less guppies in the same size tank as experts, as having more in one tank starts to make things a little harder. Most people would recommend increasing the amount of space accordingly with the amount of guppies.

While the rule is that you need 1 gallon for each inch of fish, if you have 20 fish, each 2 inches long, so 40 inches of fish, you might actually want to keep them in a 50 gallon tank. However, as long as you stick to the minimum spatial requirements, all should be just fine.

How Many Guppies In A 5 Gallon Tank?

So, based on our simple mathematical equation above, it stands to reason that in a 5 gallon tank, you can have 5 inches worth of guppies. So, this means that you could keep 2 females, or 3 at most if you want to push it.

You could keep 3 males in a 5 gallon tank as well. You could also keep 2 males and 1 female, but that is not recommended because they will most likely breed.

The point to remember is the 1 inch of fish for 1 gallon rule. Beginners especially need to stick with this. However, a more experienced fish keeper could probably house around 4 or 5 guppies in this space, as long as none of them are too large. Never go over 1.5 inches of fish for every gallon of water.

Other Guppy Keeping Tips

A Suitable Filter

Make sure to have a good filtration unit that engages in all 3 major types of filtration. All 3 types, including mechanical, biological, and chemical filtration are important. However, the most important aspect here is to have a good biological filtration system.

Also, ensure that you have pretty fine substrate, a few good plants, and a decent lighting system too.


Make sure that guppy tank water is always between 74 and 82 degrees Fahrenheit, with the ideal being around 78 degrees. These little guys are tropical fish and they do not do well in cold water (more on tank temperature on this article).


Make sure to feed your guppies good food. Some high quality tropical fish flakes should do just fine. You can also supplement some meals with freeze dried krill, baby meal worms, and insect larvae too.

Tank Mates

Guppies are quite peaceful, which means that you should keep them with other peaceful community fish. They won’t do too well with fish that are much larger, faster, or more aggressive. While these little guys look cool, they won’t be able to stand up to larger and more aggressive fish too well.

Commonly Asked Questions

How Many Guppies Should I Get?

Guppies are pretty easy going fish and if absolutely necessary, they can be kept alone, for instance if you have a very small tank. Now, while they can be kept alone, it really is not recommended at all.

Guppies are usually seen in groups, and having at least 4 or 5 is recommended, as they do like to be around each other. Keep in mind that if you only want 2, you should only keep males, and anymore than that, and you want to keep guppies at a ratio of 2 males to 1 female.

How Many Guppies In A 3 Gallon Tank?

Generally speaking, a single guppy requires 2 gallons of tank space in order to be happy and healthy. Therefore, in a 3 gallon tank, you should still only keep a single guppy.

Sure, you could jam a second one in there, but they really will not be happy at all. They don’t want their space to be cramped. Mathematically speaking, you can keep 0.5 guppies per gallon of water.

How Many Guppies Can You Have In A 10 Gallon Tank?

Alright, so the ideal guppy tank size is 2 gallons per fish, so let’s just divide 10 by 2, which leaves us with a total of 5.

You can keep 5 guppies in a 10 gallon tank and they should be fairly comfortable.

How Many Guppies Per Litre?

So, a gallon of water is 4 litres of water. We have already figured out that each guppy requires 2 gallons of water of tank space to be happy, which means that each guppy requires a full 8 litres of water.

Therefore, you cannot keep any guppies in a single litre of water as they require at least 8.


As long as your guppies have enough room and you treat them right, they should live to old age no problem. Just remember that you should not keep more than 1 inch, or 1.5 inches at most, of fish per gallon of water. Therefore, in a 5 gallon tank, keeping more than 3 or 4 guppies is not recommended.