A tortoise enclosure requires a substrate to cover the bottom of the tank or table. This absorbs waste, maintains humidity levels, gives the tortoise a surface to walk on, and provides digging opportunities.
Sand is a readily available option at pet stores. However, you may have read stories online claiming that a sandy substrate can harm tortoises.
Sand is advantageous because it won’t rot no matter how wet or dirty it gets, it’s enjoyable for tortoises to dig in, and it’s cheap to buy.
However, there are hazards to using sand as your substrate of choice. So, mix sand with soil or choose another type of tortoise substrate.
Can Tortoises Live on Sand?
Tortoises can live on sand. Certain species hail from the desert or tropical climates, where they encounter sand. Alongside other soil types, these tortoises are forced to burrow, walk on, and eat sand.
In particular, desert tortoises and Galapagos giant tortoises are well-adapted to living on sand. Were you to house them in a sand-filled vivarium, they would feel at home.
Even species that don’t encounter sand in the wild may enjoy its consistency and texture because it’s easier to dig in, thermoregulate with, and hide eggs within.
Is Sand Bad For Tortoises?
While sand is a substrate that wild tortoises live in, you shouldn’t fill your tortoise enclosure with sand. Not every tortoise will be harmed by it, but there are risks for tortoises.
Using another substrate can fulfill the same benefits of sand without the hazards. Problems that might arise from using this substrate include:
Impaction
Most sand used as a substrate has large grains, so it won’t be easy to digest if the tortoise consumes any, especially compared to regular soil.
Once inside a tortoise’s digestive tract, grains of sand can easily accumulate and lead to colonic impaction—this extreme type of constipation results in delayed or failed excretion.
The effects of impaction on a tortoise can be fatal. The more sand your tortoise eats, the greater the danger. Your pet tortoise may eat the sand accidentally when its food becomes coated in the sand, or it may do so purposefully out of:
- Curiosity
- The need for minerals
- The compulsion to eat non-food items, such as pica.
Even if the tortoise survives, the Journal of Herpetological Medicine and Surgery shows that impacted tortoises may struggle with digestive issues long-term.
This can lead to an inability to glean the proper nutrients from food, resulting in weight loss and lethargy.
Eye Irritation
Sand particles can easily enter your tortoise’s eyes as it burrows or plays within its enclosure. In most cases, a few particles in the eyes will not cause more than ‘painful blinks.’
However, if many particles accumulate inside the eyes (which is more likely with sandy substrate), it could lead to serious eye problems, such as corneal abrasions. These will be painful for the tortoise and may lead to damaged vision or blindness.
Unlike other soil types, dry sand is more likely to get kicked up as a tortoise plays and digs. Even if you water the sand to minimize this, the substrate is unlikely to retain the water.
Low Humidity
Because sand is poor at retaining water, it’s difficult to maintain or balance the humidity levels of a tortoise tank when sand is the base substrate.
Proper soil contains porous particles that can become tightly packed together. This keeps water from passing through easily, thus retaining moisture and allowing you to add humidity to the tank with regular misting.
All tortoises, regardless of species, need a certain degree of humidity in their environments. This helps to prevent dehydration, as tortoises absorb water to stay hydrated through their skin and digestive system.
In humid environments, the moisture in the air can seep into a tortoise’s body through the permeable carapace. This simultaneously reduces the need to drink water and replaces body moisture lost during regular activities or urination.
According to the University of Veterinary Medicine, tortoises that grow up in low-humidity environments have a greater risk of shell pyramiding. Low humidity levels can dry out the eyes and nose, making your tortoises more susceptible to bacterial infections.
These infections can significantly impact a tortoise’s quality of life and weaken its immune system.
Hard to Walk On
Turtles possess flippers and flexible wrists adapted to walking on sandy ground and have claws and toes. After all, they’re designed to walk on more solid surfaces.
Furthermore, tortoises are technically digitigrades, which means they walk on their toes like elephants and dogs. With sand particles being so loosely held together, tortoises often struggle to walk normally on sandy ground, and their toes and claws will instead sink into the ground as they move.
This may not be a problem in a tiny enclosure (which should not even be an option in the first place), but if your tortoise lives in a larger vivarium, the traction problems can become exhausting.
Soil And Sand Mix For Tortoises
Despite causing problems for pet tortoises, sand is often cheaper and more readily available than other substrate materials. So, some owners prefer it for their tortoise enclosures.
If you must use sand for your pet tortoise, there are tweaks you can make to modify the sand and ensure it’s safer for your tortoise. Here are some approaches:
Mix with Loam
Many chelonian experts recommend mixing soft sand with soil, preferably loam compost. This is a way to combine their advantages and retain the optimal amount of humidity.
The mixing ratio depends on the species of tortoise. For instance, the sand composition should be higher (ideally a 70:30 ratio) for desert and arid species. Meanwhile, the amount of loam should be higher (60-70%) if you keep more standard tortoise breeds.
To prevent moisture loss and sand ingestion, include other materials (like mulch and leaves) in the mix. This will help cover the sand and keep the substrate mildly wet; that way, your tortoise’s eyes and nose do not become irritated.
For the best effect, place them at the top of the substrate.
Add Some Humidity
A sandy substrate is helpful if you have an arid species, like a Russian or gopher tortoise.
However, you’ll need to artificially increase the air moisture content to closely replicate the levels of these species’ natural environments.
Get a digital thermometer or hygrometer, along with a spray bottle. Research the exact humidity requirements of your tortoise; most are comfortable at anywhere between 30-60% humidity.
After that, take hygrometer readings daily and mist the enclosure. Apply extra misting if the levels go below 30%.
Alternatives to Sand
If you’d prefer to remain on the safe side and avoid sand altogether, many substrates offer similar benefits without the dangers. The most popular include:
Top Soil
As land-based animals, tortoises are used to walking and living on topsoil, which makes it an ideal substrate. With topsoil, humidity levels are easy to maintain, and the tiny particles and digestible nature of topsoil eliminate the risk of impaction.
Ideally, you should use soil devoid of chemicals, particularly fertilizer and pesticides. To this end, you can buy a packet of sterilized topsoil from a pet store.
Moreover, you can mix the soil with other materials, such as peat moss. This can prevent the soil from getting muddy when the tortoise spills water or when the humidity levels are high.
Coconut Coir
Coconut husks are an increasingly popular substrate material for reptiles and small animals, primarily because of their wide range of textures.
For tortoises, coir grade is recommended, as it consists of very finely-ground husks. It’s natural, lightweight, unlikely to cause impaction, and inexpensive.
The only downside is that it’s highly absorbent and needs to be regularly misted.
Sphagnum Moss
This is a safe and popular substrate for smaller tortoises. It’s especially ideal for tortoises that originate from warm, humid environments, like the red-foot tortoises.
Its main advantage is that it’s easy to burrow into, even for hatchlings, and boasts a high water retention rate. It’s also easily digestible, and some tortoises love its taste.
A downside is that high-quality sphagnum moss is rather expensive. The cheaper options are more susceptible to bacterial and fungal infestations.
