8 Snakes that Fit in a 20-Gallon Tank

Written by Kristen Holder
Updated: June 29, 2023
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Key Points

  • Rough green snakes are their striking green color so that they blend into their natural environment.
  • Garter snakes usually are 2-3 feet long, though the longest garter snake ever recorded was 4.4 feet long.
  • Native to arid regions in Africa, Kenyan sand boas only grow to a max of about 2 feet long.
Snakes that Fit in a 20-Gallon Tank infographic
Only snakes up to four feet long should be kept in a 20-gallon tank.

Considering how long snakes can be, finding the appropriate snake for a 20-gallon tank needs to be a calculated decision to ensure you’re able to provide top-notch care to your pet. All 8 snakes on our list are nonvenomous.

A snake is almost always kept in a 20-gallon long tank to accommodate a longer snake. Almost all snakes have a sizeable lifespan, so any snake is a long-term commitment. Only snakes up to four feet long should be kept in a 20-gallon tank.

Most snakes will use a substrate made from shavings, and you must never use aromatic shavings as these will cause respiratory problems. All snakes will also need a hot side and a cool side for their tank, which can vary a few degrees based on species and the individual in question.

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So what are eight snakes that can comfortably fit into a 20-gallon tank their entire lives? Let’s go over some details of these snakes now.

1. Rough Green Snakes

rough green snake on rocks

Rough green snakes grow to be about two feet long.


Rough green snakes are their striking green color so that they blend into their natural environment. They prefer forests, wetlands, and uplands. Their diet mostly consists of insects. They’re usually between 1.5 to 2 feet long, but they can grow up to 3 feet in length. Wild-caught specimens can be tamed and made into good pets. A captive rough green snake has a lifespan of about 15 years.

2. Garter Snakes

garter snake vs rattlesnake

Garter snakes make great pets if you don’t capture a wild one.


Garter snakes usually are 2-3 feet long, though the longest garter snake ever recorded was 4.4 feet long. Their wild habitats are forests, wetlands, fields, and woodlands. They live up to 5 years in the wild and up to 10 years in captivity.

While garter snakes are common and make great pets, it is not advised to capture a wild snake. It won’t have the same demeanor as a pet snake, and it will do anything it can to protect itself, including biting and releasing an offensive odor.

For an unknown reason, garter snakes in captivity react to their specialized diet by developing a smaller head than their wild counterparts. When reintroduction campaigns are undertaken, the survival rate of captive specimens is lower than desired, presumably because the snakes do not have sufficient access to the prey they need due to their head size.

3. Kenyan Sand Boas

Kenyan Sand Boa - Face

Kenyan sand boas are great for a 20-gallon tank because they are small.


Native to arid regions in Africa, Kenyan sand boas only grow to a max of about 2 feet long. They’re easy to care for, and they’re known for being docile, so they make great beginner snakes.

While it’s not recommended that sand be used with most other snakes, the Kenyan sand boa needs a sand substrate. Once per day, waste and other litter will need to be scooped out of the sand. The entirety of the sand in the enclosure should be replaced at least once every three months.

4. California Kingsnakes

Best Pet Snakes

While most kingsnakes are too small for a 20-gallon tank, California kingsnakes are the appropriate size.

©Creeping Things/Shutterstock.com

While most types of kingsnakes are too large for a 20-gallon enclosure, California kingsnakes are the appropriate size. Because they’re so popular, their personalities have been bred to create a more docile animal, and it’s easy to find a California kingsnake breeder. These snakes are great at escaping. Exceptional care must be taken to ensure that the lid is securely fastened to the enclosure and that any holes or other opportunities to vacate the vivarium have been eliminated.

5. Rosy Boas

Three lined rosy boa

Rosy boas are unusually slow and docile.

©Nathan A Shepard/Shutterstock.com

Rosy boas stay small enough to fit in a 20-gallon tank. They’re unusually slow, and, in the wild, they only reach speeds of up to 1 mph. These snakes are great for beginners because they’re docile and easy to handle. Since they are constrictors, they don’t bite.

Rosy boas are considered one of the safest snakes you can own, as well as one of the cutest because of their pink coloration and stripes. These snakes are long-lived, surviving up to 40 years in captivity. They’re a great choice, but they’re a lifetime commitment.

6. Western Hognose Snakes

The Western Hognose Snake has a thick body and is slightly smaller than the Eastern Hognose.

Western hognose snakes hang out on the ground because they are burrowers.

©iStock.com/Iuliia Morozova

These snakes have a pig snout caused by a protruding scale which they use to burrow in their substrate. They hardly bite and prefer to play dead instead of attacking, making them easy to handle. They’re appropriate snakes for beginners.

Western hognose snakes like to hang out on the ground, so the bigger the floor space you can give them, the better. Their substrate needs to be deep and appropriate for burrowing, as they spend most of their day rooting around on the bottom of their tanks.

There are a lot of morphs available in an array of colors and patterns.

7. Red Milksnakes

common red milksnake curled up

Red milksnakes quickly adapt to being handled.


Red milksnakes live up to 22 years in captivity and grow up to a length of 2.5 feet. They don’t bite since they are constrictors that squish their prey between their coils to kill them. These snakes are adaptable and can be acclimated to handling even if they’re wild-caught. They make great beginner snakes.

8. Male Corn Snakes

snake on the ground in leaf litter

Only male corn snakes can be kept in a 20-gallon enclosure.

©Nathan A Shepard/Shutterstock.com

Male corn snakes are a popular choice among first-time snake owners because they are docile and curious. They like to explore their enclosure, which makes them one of the more entertaining snakes as opposed to a more sedentary choice.

You’ll need to make sure that you’re obtaining a male corn snake for your 20-gallon tank, as females grow to be too large. The smaller males, however, are appropriate for a 20-gallon enclosure.

Too much space may have negative consequences on a corn snake, so while this snake is one of the largest on this list, it’s still appropriate for a smaller enclosure. Females can grow up to 6 feet in length, while males usually average about 4 feet.

8 Snakes that Fit in a 20-gallon Tank

List of snakes that can fit in a 20-gallon tank:

RankSnake Species
1.Rough Green Snakes
2.Garter Snakes
3.Kenyan Sand Boas
4.California Kingsnakes
5.Rosy Boas
6.Western Hognose Snakes
7.Red Milksnakes
8.Male Corn Snakes

Other Pets That Could Live in a 20-gallon Tank

If you have a 20-gallon tank and snakes just aren’t your cup of tea – consider other pets that could live happily in a terrarium habitat. Geckos and other lizards are great choices for a tank environment – as are a variety of frogs and salamanders. Keep in mind that if you want to keep aquatic pets – you will need to install filtration equipment and a water heater and a small land area for semi-aquatic pets. 20-gallon aquariums are also good homes for small rodents such as hamsters, gerbils, and mice. A mesh aquarium lid or a wire cage added to the top would provide your pet with opportunities to explore and exercise. Be sure not to place the tank near a heat source or sunny window so your little rodent pets can stay comfortable. If none of these options appeal to you – it is an aquarium – so why not get some fish?

pet fish swimming in aquarium

Many pets could call a 20-gallon tank home including lizards, hamsters, and fish!

©iStock.com/Juan Carlos Juarez Jaramillo

The photo featured at the top of this post is © iStock.com/bugphai

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About the Author

Kristen Holder is a writer at A-Z Animals primarily covering topics related to history, travel, pets, and obscure scientific issues. Kristen has been writing professionally for 3 years, and she holds a Bachelor's Degree from the University of California, Riverside, which she obtained in 2009. After living in California, Washington, and Arizona, she is now a permanent resident of Iowa. Kristen loves to dote on her 3 cats, and she spends her free time coming up with adventures that allow her to explore her new home.

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