What Reptiles Can Live In A 20-Gallon Tank?

California kingsnake living in a 20 gallon tank

A 20-gallon tank is a great size tank for reptiles and their owners!  20-gallon tanks are great for people who are not in a permanent home or have space restrictions.  But, they’re a little roomier than a 10-gallon tank and can house all kinds of reptiles.

If you’re here to find out which reptiles are best suited for a 10-gallon tank, here are our recommendations:

  • Rough Green Snakes
  • Kenyan Sand Boas
  • Five-lined Skinks
  • California Kingsnake
  • Western Hognose Snake

To figure out why these 5 reptiles were chosen, and to pick the right one for you, keep reading!

Why Would You Choose a 20-Gallon Tank?

Although 20-gallon tanks are not the smallest housing option for reptiles, they’re definitely not the largest!

So, why would you choose this size tank over another size?

It’s Not Too Big and Not Too Small!

Essentially, this tank is a great medium-sized tank!

The main reason that you would want to use a 20-gallon tank is that they’re not too big or too small, they’re just right!

The dimensions of a 20-gallon tank are generally 24in L x 12in W x 16in H.  These tanks can be arranged horizontally or vertically, depending on your retile living inside!

although you might think you need a bigger tank to keep your pet reptile happy, a smaller tank can do a great job, with the proper equipment.  A 20-gallon tank is still small enough to be able to move easily around a room, house, or apartment.  If you are in a situation where you know you will be moving in the next year or so, I recommend keeping your equipment as light as possible, so you are always able to keep your scaly friends with you!

3 Factors That Determine Tank Size

Even though two animals might weigh the same, or be the same size, they could have different housing needs.  Tank size varies by species. The right size tank for a reptile depends on a few different factors, and length is only one of those factors.

If you plan on becoming the best reptile parent possible, it’s important to get familiar with your pet’s housing needs.

1. Animal’s Length

The most easily measured factor is your pet’s length.  A reptile’s length is used to measure the width, length, and height of their tank.  But, depending on the species, they will have slightly different equations to figure this out.  Here is a table that can provide general housing guidelines for pet reptiles!

As you can see, snakes, lizards, aquatic turtles, and terrestrial turtles all have different equations to determine tank size!  Luckily, all you need to do is determine or know the adult length of your species to get them the best size enclosure!  But, why do the equations vary between species?

2. Activity Level

Activity level is one of the reasons that tank size varies by species!  The equations above take each species’ activity levels into account.  And remember, the table above is just a guideline, some snakes can need more or less space depending on how active they are.

You can think about this factor by imagining the difference between the housing needs of a grumpy old cat and a young playful puppy!  Even though these animals might be a similar size, their species and individual qualities mean that the space they need is very different!  Obviously, the puppy would need a lot more room to roam and run than the cat!

3. Environmental Needs

If you’re already a reptile owner, you know how important their environment is for their health.  If you’ve never owned a reptile before, get ready to do some research!

Our reptile friends come from all over the world and live in all different sorts of climates.  This means that some will require warmth, humidity, darkness, or even special lights!  When considering tank size, environmental needs also determine whether your tank will be set up vertically or horizontally.

Arboreal (climbing) species need space to climb in their enclosure!  This usually means you will need a tall tank, with plenty of branches and vines inside.  Terrestrial (ground-dwelling) species are more inclined to walk or slither close to the ground and usually need a lot of horizontal space to do this!

If your pet reptile has special temperature or humidity requirements, this could also affect tank size!  To keep a tank very humid, you might want to choose a smaller option.  However, if your reptile needs a temperature gradient where one side of the tank is warmed than the other, you will definitely need a longer tank.

Keeping these factors in mind, let’s see why these 5 reptiles make great choices for a 20-gallon tank!

5 Best Reptiles For A 20-Gallon Tank

In my opinion, the following reptiles can be housed in a 20-gallon tank for the duration of their adult lives!  Keep in mind if your pet is larger than the normal for each breed, you might need to consider sizing up.

In addition to these reptiles, all of the pets we approved for a 10-gallon tank will also live comfortably in a 20-gallon tank.  If you’d like to see that list, click here.

Rough Green Snake

Length: 22-32 inches / Life Span: 15+ years

Rough green snakes are some of the cutest, slinkiest snakes around!  Their bright vibrant color makes them a beautiful pet to look at.  And, they are extremely handleable when raised in captivity.

Roush green snakes are arboreal, which means their tank needs to be vertical!  They require lots of vines to climb on and leaves to hide behind.  Green snakes can also do well in groups with other green snakes.  Even though these snakes can be very handleable, they aren’t great beginner snakes because they are shy and difficult to feed.

I know you’re thinking these snakes can grow to be too long for a 20-gallon tank.  But, these snakes are super thin and fit much more comfortably in a tank this size than a thicker snake of their length would.

Kenyan Sand Boa

Length: 20 – 24 inches / Lifespan: 15 – 20 years

Kenyan Sand Boas might be the best reptile for a beginner looking to fill a 20-gallon tank.  These snakes are calm, friendly, and easy to care for.

Originally from Africa, Kenyan sand boas are terrestrial species, that like warm areas where they can lie on.  Despite their name, they do not need a sand-filled enclosure.  Many of these snake species can spend their whole adult life in a 10-gallon tank, with only a large female ever really needing a 20-gallon tank.

A 20-gallon tank for this reptile should be set horizontally, with a substrate for burrowing and holes to hide in.  After some warm-up time, your sand boa should start to come out of its hiding holes!

Five Lined Skink

Length: 5-8 inches / Lifespan: 6 years

Five-lined skinks are super cute, super small, and can live a full life in a 20-gallon tank.

Five-lined skins are native to the U.S. but have become common as pets.  These reptiles are shy by nature.  A good tank for a skink should include lots of places to hide and burrow.  These skinks are terrestrial, but enjoy walking and climbing.  Having pieces of bark or small logs in their vertical tank is a great idea.

Because these animals are shy, they aren’t always the easiest to handle.  Unlike blue-tongued skinks, who we describe in our 10 most handleable pets article, as being like potatoes, five-lines skinks are not as relaxed.  \They move quickly, and you should use extreme caution when removing them from an enclosure!

California Kingsnake

Length: 24 inches average / Lifespan: 20 years

In my opinion, California kingsnakes have one of the most beautiful scale patterns!  Their black and white stripes feel a little like a Tim Burton character, but they usually end up being sweet and docile.

California kingsnakes make great reptiles to keep in 20-gallon tanks.  They don’t often grow longer than 24 inches and are terrestrial species, that spend most of their time slithering on the ground.  The setup for an enclosure of a kingsnake is generally pretty simple, you need to give them some head, a place to hide, a nice substrate, and water.  These snakes won’t use branches for climbing!  These snakes are one of the species that do need UVB lighting, in addition to many other reptiles.

Kingsnakes are one of the most common snake pets because they are simple to care for and hardy.

Western Hognose Snake

Length: 24 inches average / 18-30 years

Western hognose snakes get their name from the upturn of their snouts.  these snakes are docile in the wild, and prefer to hide from predators rather than attack them!

The same is true for these snakes as pets.  For the most part, these snakes enjoy being cozy and coiled up under a nice rock.  These reptiles are terrestrial and love warmth.  They make a great fit for a horizontally arranged 20-gallon tank.

While the majority of these snakes grow around 24inches, some members of this species can grow up to 3.5 feet in length.  And because these snakes are so long-lived, if you end up with a longer snake, you will probably need to size up to something like a 30-gallon tank.

Bonus Amphibian: Red-Eyed Tree Frog

Length: 2-3 inches / Lifespan: 5 years

While frogs aren’t reptiles, I know you would still love to hear about which ones might fit in a 20-gallon tank.  Red-eyed tree frogs are beautiful, tropical frogs that can thrive in a 20-gallon tank.

Tree frogs are naturally arboreal, so their 20-gallon tank needs to be vertical.  These frogs need room to jump and spot to land on.  They love to sleep on leaves, so having live plants in their enclosures is ideal.  Although they’re not extremely difficult to care for, they don’t make the best pet for beginners. So, if this is your first reptile or amphibian pet, these frogs won’t be your best option!

Final Thoughts!

There are so many options for reptiles that you can keep in a 20-gallon tank.  But, if you find that your animal needs more space than we recommend, size up!  When picking a tank for your pet you need to think about their length, activity level, and environmental needs.  Consult with our chart above if you’re not sure!

Remember that many young animals can be housed in a smaller 20-gallon tank but will need t to be upgraded as they mature.  Hopefully, you were able to get some great ideas for what your next pet reptile might be in your 20-gallon tank!