9 Reptiles That Can Live In A 20-Gallon Tank Forever

what reptiles can live in a 20 gallon tank

When choosing a new pet or upgrading the set-up of an old friend, you want to make sure you’re giving your reptile the best you can. Naturally, housing requirements play a big part in your preparations, especially the size and shape of the enclosure! So, if you’ve got the space for a 20-gallon tank, what reptiles can live in an enclosure that size forever?

I’ve researched nine reptiles that can happily live in a 20-gallon tank:

  • Western Hognose Snake
  • Crested Gecko
  • Leopard Gecko
  • California Kingsnake
  • Gargoyle Gecko
  • Kenyan Sand Boa
  • Pygmy Chameleon
  • Mourning Gecko
  • Electric Blue Gecko

If you’re curious about how to set up an excellent tank for these guys, keep reading! Each section of this article will focus on one of the above reptiles, detailing the enclosure size and shape requirements, heat and lighting, humidity, enrichment, and more!

Western Hognose Snake

can hognose snakes live in a 20-gallon tank

The Western Hognose Snake is a stout little colubrid with an upturned nose used for digging. It’s also well known for its harmless defensive behaviors, like playing dead and flattening its body.

The Western Hognose snake comes in a variety of colors and is easy to handle, making it a popular pet for both new and experienced reptile keepers!

Since the Western Hognose Snake is a ground-dwelling species, the height of the tank is not as important, but a 20-gallon long tank is a perfect size for an adult snake, keeping in mind that you want to maximize the amount of floor space for these diggers.

Even though they won’t be climbers, a secure top is always a must when keeping a snake!

Tank furnishings for a hognose snake can be straightforward, and a couple of hides should suffice. These guys like to burrow, so you need open space to allow them to dig.

Though these hognose snakes live and burrow in loose soil and sand in the wild, it is not a recommended substrate due to the risk of impaction.

A popular choice is shredded aspen – it allows the snake to burrow, absorbs odors well, and is easy to clean! Cedar and pine substrates are hazardous to your snake’s respiratory system, so avoid these.

Western Hognose snakes are diurnal, so full-spectrum light (UVB and UVA) should be provided for 14-16 hours a day during the spring and summer months and 8-10 hours a day in the autumn and winter.

If you’re interested in snakes’ day and night cycles, check out our informative article: Do Snakes Need Light at Night?

A Western Hognose requires a basking area with a temperature of about 90°F, which can be attained by using a reptile heat pad.

The pad should be appropriately sized to allow for a heat gradient, covering no more than one-third of the tank’s floor so your snake can move away from the heat if desired. Hot rocks are not recommended due to burn risk.

At the opposite end of the heat gradient, the cool side of your snake’s tank should be maintained from 75-80°F.

These guys need a sturdy water dish with fresh, clean water, even though they often inhabit semi-arid areas in the wild.

Change the water every other day unless substrate or other soiling contaminates the bowl – then it should be cleaned right away.

By the way, if you are interested in reptiles for 10-gallon tanks, read this article! If you are looking for reptiles for 40-gallon tanks, read this article right here.

Crested Gecko

can crested geckos live in a 20-gallon tank

Crested geckos are an ideal choice for beginner reptile owners with their easy to meet care requirements. These little guys are very popular and widely available.

Because they live in trees and love to climb, crested gecko vivariums can make excellent displays!

A tall 20-gallon tank with a screen top is perfect for a crested gecko to live in for its entire life.

The tank must be tall and equipped with enough branches and plants to give the crested gecko room to express its natural climbing behavior. Because they’re excellent climbers, a secure screen top is also a must!

As far as hides go, the crested gecko is comfortable resting in foliage and on branches, so having enough coverage in that department is essential. Artificial plants will do, but real plants will also work.

Cork bark works well for climbing sections and shelters, while angled pieces of dried wood provide areas for activity and relaxation.

Since crested geckos spend most of their time climbing, you have a variety of substrate options. If you want to grow plants inside the tank, coconut fiber mixed 1:1 with peat moss-based soil (without perlite) works well.

You can use the soil alone as a substrate as well, but reptile carpet also works for easy cleaning. Sphagnum moss and bark are good choices too!

Interested in keeping live plants in your crested gecko’s enclosure? Check out our article on 24 Plants That Are Perfect For Crested Gecko Tanks!

Like the leopard gecko, crested geckos are nocturnal. To simulate the day/night cycle, you can use a low-wattage incandescent bulb or a ceramic heater over the branches to provide a nice basking area.

Be sure to leave a cooler area for your gecko to use to regulate its body temperature.

Daytime temperatures should be between 78-82°F. In warm areas, this can be achieved without additional heat. Nighttime temperatures should be between 68-75°F.

Here are a few of our articles that will help you with getting everything right:

Crested geckos like a humidity of 60-80%, and their tanks should be misted twice a day. You can also use a cool air humidifier in the room to maintain good humidity.

It’s recommended to use a hygrometer to monitor this so you always know your gecko is comfortable. A shallow, stable dish of fresh water should be available at all times.

We also highly recommend reading this article before getting a crested gecko:

Leopard Gecko

can leopard geckos live in a 20-gallon tank

The leopard gecko is an excellent choice for a pet! In fact, it’s one of the most commonly kept lizards today.

These little guys have been captive-bred in the United States for over 30 years and come in a wide variety of sizes and colors.

Though they are readily available at pet stores and local breeders, an avid collector’s market exists for leopard geckos worldwide for rare morphs.

On average, female leopard geckos are 7-8 inches long, while males are 8-10 inches long. Compared to other reptiles, they are also long-lived, with an average life span of 6-10 years in captivity.

So, you want to make sure your leopard gecko tank is the best it can be to keep them comfortable!

A 20-gallon aquarium at least one foot tall is the perfect size for a leopard gecko to live in from hatchling to adult.

Whatever tank you choose should have a reliable screen top that can support a heat lamp and keep your gecko secured inside.

Leopard geckos require hides on both sides of the tank. When your leopard gecko is shedding, you can provide some moist moss in the hide to help with the shed.

Low branches and rocks offer great areas for climbing, giving your leopard gecko environmental enrichment.

Leopard geckos do fine on reptile carpet – this is recommended if your leopard gecko is less than six inches, as there can be risks with swallowing substrate, leading to impaction.

For larger leopard geckos, semi-arid bioactive substrates can also be used.

These little guys need a temperature gradient, so you’ll need to heat one side of the tank with a heat lamp. Heat rocks aren’t recommended because they can become too hot for leos and cause burns.

Be sure to keep a thermometer on both sides to monitor the temperature accurately! The heated side of the tank should be between 80-90°F, with the cool side between 75-80°F.

If you need help with that, we recommend our articles here:

Your tank’s humidity should be between 10-30% as well.

Leopard geckos have a 12-hour day and are typically more active at night. A low-watt UVA/UVB light on a 12-hour cycle will provide the necessary light for your little leo. Read our article here to learn how to create the perfect day and night cycle for your leopard gecko.

Leopard geckos require a stable (so they don’t knock it over!) source of fresh water at all times. Be sure to clean your gecko’s water dish daily and keep an eye out for any spills, as you don’t want the tank to become too humid.

We also recommend reading these articles before getting a leopard gecko:

California Kingsnake

can california king snakes live in a 20-gallon tank

California kingsnake is a popular variety of common kingsnake native to California.

It was one of the first snakes ever to be bred in captivity, and as a result, the California kingsnake has become one of the most common snakes kept by reptile enthusiasts.

With its large variety of colors and morphs, it isn’t hard to see why!   

Kingsnakes can grow to be about 3-4ft long, and most adults can live comfortably in a 20-gallon enclosure.

California kingsnakes are one of the smaller varieties of kingsnake, so for other types of kingsnake, or if your snake is over 4ft long, you should upgrade to something larger.

It’s essential that your tank has an extremely secure top, as kingsnakes are notorious escape artists – if there is a weakness to be found, these guys will exploit it! You can increase the security of your enclosure by using screen clips.

Like most snakes, aspen shavings are recommended as a substrate for California kingsnakes. Aromatic wood shavings should be avoided due to risk of respiratory illness, and sand should also be avoided due to the risk of impaction.  

In my research, I stumbled upon varying opinions regarding kingsnakes and lighting.

Some argue that kingsnakes don’t need any special lighting and can certainly survive without a UVB bulb, while others claim that UVB light can be beneficial to the immune system and the growth of snakes in general, allowing them to thrive (Source: 1, 2, 3).

Kingsnakes are active during the day and night, so additional lighting is recommended to stimulate natural activity during daylight hours.

Natural light can be great for your kingsnake but be sure that your snake’s enclosure isn’t in the path of direct sunlight, as this can cause them to overheat quickly.           

Kingsnakes require a basking area and a cool side of their enclosure, and hides should be placed on both sides for security. The warm side of the enclosure should be 90-95°F, with the cool side at 75-80°F.

Heat pads (be sure to get the proper size to form a good gradient) and heat bulbs can be used to heat your snake’s enclosure.

Like the corn snake, kingsnakes can tolerate cooler temperatures at night, so your heat source should be turned off at nighttime. A winter cooldown – “brumation” – is also recommended if your king snake is healthy!

The water dish provided should be large enough that your snake can immerse its entire body in it and sturdy enough so it doesn’t fall over. Water should be changed every other day or sooner if soiled.

Gargoyle Gecko

can gargoyle geckos live in a 20-gallon tank

The unique gargoyle gecko gets its name from its triangular head with cranial bumps, round eyes, and stocky body. They are mainly tree-dwellers, living in lush, moist habitats.

These little guys are perfect for beginners, as they are easy to care for, widely available, and have a friendly, docile temperament.  

An adult gargoyle gecko (about 8-10 inches long) can happily live in a 20-gallon tall tank for its entire life.

Groups of adult female gargoyle geckos can be housed together, and it’s a good rule of thumb to add 5 gallons of tank space for each additional gecko.  

Since gargoyle geckos are semi-arboreal in the wild, they need plants and branches to climb on in their enclosure. They also like to hide in ground plant cover as well!

Your gargoyle gecko terrarium should be well-stocked with branches, plants (either live or artificial), vines, and hides (hide boxes, PVC pipes, or small birdhouses) to provide optimal enrichment!

An informative video on making jungle vines for your terrarium!

Substrates that can hold moisture, like Reptisoil or moss blends, work well for gargoyle geckos. Natural substrates like these should be spot cleaned daily and replaced each month.

Bioactive substrates can be a great option if you’re growing plants inside the enclosure, as they create a self-cleaning terrarium.  

Gargoyle geckos require temperatures between 77-84°F. Since this is the average ambient temperature of a home, it can be quite easy to keep your gargoyle gecko comfortable.

Incorporate a basking area and a cool side of the enclosure with a heat bulb (white or clear low-watt incandescent bulbs work well) if you can, but be sure to monitor the temperature with a thermometer not to overheat the enclosure.

A gargoyle gecko’s basking area should be around 84F, with the cool side at 73-74°F.

Gargoyle geckos are comfortable at a humidity level of about 50-70%.

Mist your gecko’s enclosure daily, making sure to monitor the humidity level with a hygrometer so you don’t overdo it – too much humidity can cause mold growth and make your gecko sick!

Misting is also a great way to provide adequate hydration to your gargoyle gecko, as they often don’t drink standing water from a bowl – instead, they lick the water collected on the plants and sides of the enclosure.

However, you should always provide a small water dish for your gecko regardless.

Kenyan Sand Boa

can kenyan sand boas live in a 20-gallon tank
Kenyan Sand Boa (male)

Kenyan sand boas are on the smaller side – about 12-24 inches long – and perfect for a 20-gallon tank! As you may have guessed, they’re native to arid and semi-arid portions of east Africa.

Kenyan sand boas make great pets for beginners due to their docile nature, small size, and easy care requirements.

Depending on how large your Kenyan sand boa is when fully grown, a 10-gallon, 15-gallon, or 20-gallon tank is suitable.

Of course, bigger is usually a better option, so if you’re planning on housing one of these guys in a 20-gallon tank forever, that would be a great choice!

Since Kenyan sand boas live in the desert, sand is an excellent substrate for them! Commercial sand substrates for reptiles are widely available, including ReptiSand and Desert Sand.

As with any snake, any soiling should be removed daily, and the contaminated substrate should be scooped out. The entire substrate layer should be replaced every 3 months.

These guys like to burrow and will usually bury themselves in their substrate. To offer further environmental enrichment, add some branches, artificial plants, or cork hollows to the enclosure alongside the cool and warm hides!

The basking surface of the enclosure should reach a temperature of 93-95°F – this can be achieved with a 50-watt halogen flood bulb.

It’s also a good idea to place a hide box beneath the basking surface as a warm hide. The cool zone of the enclosure should be 78-83°F. Heat can be turned off at nighttime.

As mentioned above, Kenyan sand boas can technically survive without UVB light (they are mostly nocturnal) but recent studies have shown that UVB light can benefit snakes, so I would recommend using a UVB bulb in your snake’s enclosure!

Kenyan sand boas are an arid species, and therefore, they are very tolerant of hot and dry environments.

The enclosure should be kept mostly dry, but when your snake is shedding, you can offer a hide with moist sphagnum moss inside to assist with the shed.

Of course, a small water dish should contain fresh water at all times and be scrubbed out weekly.

Reptiles that can live communally in a 20-gallon tank

So far, we’ve explored caring for reptiles that can live alone in a 20-gallon tank. However, this tank size can offer enough living space for several small critters!

Let’s look at three options: the pygmy chameleon, the mourning gecko, and the electric blue gecko.

Pygmy Chameleon

can pygmy chameleons live in a 20-gallon tank
Rhampholeon Brevicauda, only 2 inches long

These little guys are only 3-3.5 inches long as adults and are generally easy-going and good-tempered. They have a unique look, with a small stubby tail and muted colors, sometimes with stripes in green, brown, or a light red.

Due to their small size and good nature, pygmy chameleons do well in an enclosure with others of the same species.

However, you should avoid housing multiple males together, as they may not get along. You can house female chameleons together, or, if you intend to breed them, no more than one male per tank.

A single pygmy chameleon requires approximately 5-gallons worth of tank space. So, for our proposed 20-gallon tank size, you could fit three or four chameleons!

Horizontal space is important because these little guys aren’t climbers, so a 20-gallon long tank would work well for each chameleon to establish its own space.

Since pygmy chameleons live on the forest floor, their enclosure should resemble their natural environment by including many plants!

Either artificial or real plants can be used – if you’re going with real plants, some good selections are golden pothos, croton, and hibiscus.

Small sticks or branches (small enough for your chameleons to climb on) also make an excellent addition.

Because pygmy chameleons don’t get a ton of sun in the wild, special lighting isn’t a strict requirement.

They do need a 12-hour day/night cycle, and UVB is optional but recommended for its demonstrated health benefits in reptiles. These little guys like a temperature between 65-80°F, close to room temperature!

Coconut bedding works well as a substrate for pygmy chameleons. If you’re growing your own plants in the enclosure, be sure to include some gravel beneath the coconut bedding to facilitate drainage and avoid root rot.

Real plants and an absorbent substrate will also help keep the tank humid, as pygmy chameleons require a humidity level of about 60-80%.

Misting twice a day is essential to maintain this, but it’s important for another reason – chameleons don’t drink standing water and will lick the droplets from plants in the enclosure!

Mourning Gecko

can mourning geckos live in a 20-gallon tank

The mourning gecko is tiny – only 3.5-4 inches long, tail included!

Mourning geckos are also entirely female and reproduce by parthenogenesis, essentially making each mourning gecko a full or partial clone of its parent. If you’re looking for a unique pet, this is it!

Since all mourning geckos are female, you can house them in groups without worrying about male dominance and infighting.

A group of three mourning geckos can live comfortably in a 10-gallon tank. Allowing for an additional 5-gallons of space per gecko, a 20-gallon tank could house up to five geckos!

Mourning geckos are an arboreal species, so a 20-gallon tall front-opening tank is recommended. Security is of utmost importance since these guys are so tiny and so good at climbing!

When hatchlings inevitably appear, you can remove them to give the little guys their own space to grow.

However, hatchlings can be successfully housed in the same tank as adults provided there is enough space – if not, adult mourning geckos have been known to eat their young.

Speaking of hiding places, branches with plenty of foliage are a must for mourning geckos due to their arboreal nature.

Plants (natural or artificial), ledges, and vines will keep them happy, busy, and healthy while providing safe spaces for each gecko.

Even though mourning geckos are nocturnal, some reptile keepers believe that providing lighting (including UVB) helps regulate their circadian rhythm and makes a difference in the growth of hatchlings.

A basking area with a temperature of 80-85°F should be provided using a low-watt incandescent or halogen bulb. The cooler area of the enclosure should rest at 70-75°F, with nighttime temperatures decreasing to 65-72°F.

Mourning geckos require an ambient humidity level of 60-80%. Mist the enclosure twice a day to create droplets all over.

Substrates like Reptisoil or sphagnum moss will also help hold humidity. Like chameleons, mourning geckos also drink water droplets from plants instead of drinking from a water dish.

Electric Blue Gecko

what reptiles can live in a 20-gallon terrarium?

The electric blue gecko is beautifully unique with its striking color and tiny size – as adults, these guys are only 2.5-3.5 inches long!

Multiple electric blue geckos can be housed in the same enclosure provided they have enough private space for themselves.

A pair of electric blue geckos can live comfortably in a 10-gallon tank, and 3-4 can live in a 20-gallon tank.

If you’re planning on housing these geckos communally, multiple males should not live together. One male can be housed with multiple females for breeding purposes, or you can house all female geckos in the same enclosure.

Since these geckos love to climb, vines, plants, branches, bamboo, and cork bark are all good options for environmental enrichment.

Electric blue geckos also require a raised ledge for food and water, as they’re used to eating and drinking off the ground.

A substrate that mimics their natural environment, such as Reptisoil or Eco Earth is an excellent choice. These hold moisture as well, assisting with the required 60-80% humidity level in the enclosure.

Be sure to mist the tank twice a day!

Electric blue geckos require a 12-hour light cycle, and UVB is required. Basking temperature should be 90-95°F, while the ambient enclosure temperature should be 75-80°F.

Nighttime temperatures can drop down to as low as 65°F. A low-watt incandescent heat bulb should do the trick!

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