Tortoises lose body moisture when performing regular daily activities, such as urinating and breathing.
To avoid dehydration, tortoises need to live in humid environments. Without sufficient humidity, tortoises can get sick, experience development problems, become less active, and refuse to eat.
To measure the humidity level in a tortoise enclosure, use a hygrometer. Then, you can maintain the humidity in a tortoise tank by adding a large bowl of water, plants, and a moist substrate.
Other options include misting, using a humidifier, and covering the tank.
It’s not enough to ensure that the tank is humid. Tortoise species have different needs, and too much humidity can cause health problems.
Making a tortoise’s environment optimal is about maintaining proper humidity levels, not making its living space as humid as possible.
Why Do Tortoises Need Humidity?
A humid environment enables the tortoise to avoid various health problems and discomfort.
Low humidity often leads to problems like:
- Shell cracking
- Eye infections
- Dehydration
- Weakened immune system
- Nose infections
- Digestive issues
- Poor shell growth
When tortoises live in dry environments, the lack of moisture irritates their eyes and noses. This is why infections in these areas are common when humidity levels are inadequate.
Aside from irritation, an infection can be caused by bacteria that accumulate in dry places. Bacteria are more likely to survive whenever the humidity level falls below 40%.
The water that tortoises drink isn’t always enough to keep their body hydrated. Tortoises lose a surprising amount of moisture by completing basic biological functions, such as defecating, urinating, moving about, and breathing. Also, staying near heat sources causes them to lose moisture.
To stay hydrated without relying on water, tortoises need a humid environment. Their carapace is absorbent, so they can avoid dehydration by taking in moisture in the air.
How To Increase the Humidity in a Tortoise Tank
You can raise the humidity in a tortoise tank by including things that will increase the humidity levels inside. Also, you can cover up most of the tank’s ventilation.
Before you do this, find out the optimal humidity level for your tortoise species. Every species has different needs, so you don’t want to go under or over in terms of the humidity.
There are various ways of increasing the humidity levels in an enclosure, including:
Bowl of Water
The most common method is placing a small bowl of water inside.
Usually, this bowl is separate from the bowl that the tortoises use for drinking. It’s placed in an area of the tank inaccessible to the tortoise, so the contents aren’t spilled over.
You’ll need to replace the water every few days, so it doesn’t accumulate bacteria.
Humidifier
A humidifier is a device that increases the humidity level of an area by releasing moisture into the air.
If you have a home humidifier, don’t put it inside your tortoise’s tank. It’s dangerous to place an electronic device anywhere near your tortoise.
There are many humidifiers for reptile tanks. Depending on the kind of humidifier you buy, you can set it on a cycle to automatically keep the humidity at the right level.
All you’ll need to do is refill it with clean water occasionally.
Misting
Misting is when you spray water inside the tortoise’s tank. Also, you can use this method to directly spray some water onto the tortoise to absorb the moisture.
Misting is like using a humidifier, but you do it manually instead of via a machine.
Using Damp Substrate
A moist substrate works well because it raises the humidity levels in the tank for a long time. Also, it’s easy to obtain since you dip it in water until the substrate is damp and spread it around. Spraying substrate with a bottle is usually insufficient.
According to the Journal of Thermal Biology, this may help your tortoise retain body moisture. The best substrates to raise humidity levels are as follows:
- Cypress mulch
- Coconut coir
- Peat moss
Only dampen a portion of the substrate to see if your tortoise likes it.
Covering Ventilation
The humidity inside the tank can escape through any opening in the tank.
To increase the humidity level, close off some of these openings. Of course, you should never completely close off the tank because tortoises still need to breathe.
Adding Live Plants
Live plants make the tank environment more enjoyable for the tortoise because they provide shade, hiding places, and encourage exploration.
Ensure that the plants are safe for tortoises, such as:
- Lemon balm
- Turtle vine
- Dandelions
- Aloe vera
- Red sorrel
- Geraniums
The downside to using plants is that tortoises eat them. If you can’t constantly replace the plants in the tank, this method isn’t a good long-term solution. Also, avoid any toxic plants.
Is Too Much Humidity Bad for Tortoises?
In the same way that low humidity can be a detriment to a tortoise’s health, too much humidity can be just as bad. Raising the humidity levels of your pet tortoise’s environment isn’t enough.
Monitor the humidity levels to ensure they don’t exceed the optimal level for the tortoise species.
Too much humidity can cause mold growth inside the tank, leading to illness and respiratory problems. Also, high humidity can cause shell rot, which causes the shell of a tortoise to deteriorate.
Tortoise shells are absorbent, so if there’s mold or bacteria in the air’s moisture, the shell will absorb it.
Does Low Humidity Cause Pyramiding in Tortoises?
Low humidity may have something to do with pyramiding in tortoises.
According to the Journal of Animal Physiology and Animal Nutrition, tortoises in dry environments experienced more pyramiding than those in humid environments.
Pyramiding occurs when a tortoise’s shell grows upwards, making each shell scute look like a pyramid. Pyramiding is irreversible, so once the deformity becomes extreme enough, it can reduce the tortoise’s quality of life. When a tortoise has a shell with pyramids, it’s considered a deformed shell.
Pyramiding is associated with a poor diet more than low humidity. Low humidity has been shown to weaken tortoise immune systems and may advance pyramiding.
How To Measure Humidity in A Tortoise Tank
A hygrometer is a tool that measures the humidity levels of an environment.
When it comes to measuring tank humidity, some owners like to monitor it themselves. This isn’t recommended, especially if you’re a new owner.
While you can tell when a tank is humid enough with condensation on the glass, it’s difficult to know if the tank is the right amount of humidity for the tortoise without a hygrometer.
How Much Humidity Does My Tortoise Need?
Tortoise species come from different regions with varying degrees of humidity.
Use the chart below to set the humidity level for a tortoise’s tank:
| Tortoise Species | Tank Humidity (Adults) |
| Sulcata Tortoise | 40-60% |
| Russian Tortoise | 30-50% |
| Leopard Tortoise | 40-60% |
| Red-Footed Tortoise | 70-80% |
| Hermann’s Tortoise | 50-80% |
| Horsefield Tortoise | 50-80% |
| Indian Star Tortoise | 70-85% |
| Cherry Head Tortoise | 70-80% |
Juvenile tortoises need higher humidity levels as they dehydrate faster than adults. Most juvenile tortoises of any species will need tank humidity levels between 60-80%.
The humidity promotes proper carapace growth. Once the tortoise is an adult, the humidity levels can be lowered as long as they stay within the correct range.
