Understanding Substrates for Crested Geckos
By: Jason
Last Updated: March 27, 2023
There are many components of a healthy habitat for a pet lizard. It is best to have the right size tank, the correct temperature, and the humidity and to fill it with the things that let your pet feel safe and comfortable. But what about the material you place at the bottom? How do you pick the best type of substrate for crested geckos?
A healthy crested gecko substrate helps promote a humid environment and won’t harm them, which includes a low risk of ingestion and the absence of dangerous chemicals. Both artificial and natural substrates can work well.
For an arboreal species, the flooring of a tank might not seem like a big deal. Let’s explore the options and learn what you can use to keep your crested gecko healthy.
Introduction
Substrates are the surface where an animal lives. There is more than one ideal substrate, as each species has its own needs.
One way to categorize different substrates is whether it mimics the natural habitat. Natural substrates, like eco-earth and organic potting soil, create a home that mirrors where they live in the wild. Some artificial materials also work and are popular because of their low cost, ease of cleaning, and low risk of impaction.
A bioactive enclosure uses live plants and animals to create a self-contained world with particular soil needs. First, it has to support plant growth. Next, it must be porous and allows excess water to pass through it, similar to how it would go outside. In a naturalistic terrarium, this is accomplished with a drainage layer that wicks moisture away and allows it to evaporate. The resulting bioactive environment manages the waste and looks great.
When thinking about crested gecko care, humidity management can be a challenge. The perfect substrate for cresties improves humidity in terrariums by retaining moisture and releasing it into the air over time.
Let’s go ahead and explore the various options.
Top Substrate Options
Natural Blends
One of the best approaches comes from combining several different natural products.
Crested gecko owners like them because they are made specifically for this reptile species. There are several popular choices, and they use peat moss, fine sand, soil, and clay. The combination retains water without feeling wet, which prevents fungal and bacterial growth.
These mixes work for a bioactive setup and for those without isopods.
Zoo Med’s Reptisoil and Lugarti’s Natural Reptile Bedding are excellent choices.
Coconut Fibers
Coconut husk and coconut coir are both excellent components in bedding material. The coco fiber makes air pockets while still holding water, making it ideal for humid habitats. Coco coir also naturally resists mold and fungus and absorbs odors while offering a naturalistic environment that complements many different tank setups.
What is the difference between these two? Coconut husk comes in larger chunks, while coconut coir is broken into fibers. Although your pet should consume neither, coconut coir is considered safe if ingested, while there is more of a risk of impaction with the husk.
Some keepers use coconut husk fibers for their bioactive enclosure. Mix half coconut fiber and half organic potting soil when making a homemade mixture.
Zoo Med’s Eco Earth coconut fiber substrate is made from husks of coconuts and is a trusted brand.
Moss
Sphagnum moss, sphagnum peat moss, and peat moss are popular substrates. (Note that each of these terms is actually a different thing but is often used interchangeably.)
Sphagnum moss is a living form of the plant and grows on damp surfaces. It has a dense, bushy texture with fibrous plant parts. Peat moss is a decaying version of the same plant and is often sold mixed with other plant matter.
While they are different, they all hold water well.
There are lots of other reasons why this is a frequent choice. First, the shape and texture make it less likely an adult crested gecko will accidentally ingest it, which decreases the impaction risk. The moss resists mold, making it less likely to cause health issues. Next, it is soft and springy, making it easy for your pet to walk on.
All of these things together make sphagnum moss an excellent substrate.
Soil Substrate
Soil is an excellent substrate for crested geckos and gives them a natural environment to thrive, but there are some things to pay attention to when selecting.
Avoid any product which contains insecticides, herbicides, or pesticides, as those are dangerous chemicals and can hurt your pet. Most, however, are fine, including those with vermiculite and perlite, the little white balls in soil. Reptile lovers have used those materials for years without problems.
For soil to be a suitable substrate for reptiles, it needs a drainage layer beneath it. Otherwise, mold and fungal growth will likely develop as moisture gets trapped below the surface.
Another way to use soil is to include it as one of several ingredients in a homemade mix (see natural blends above).
As a note, organic potting soil and topsoil are different things. Topsoil is dirt, clay, and rocks mixed with organic material. It is dense, heavy, and packs down easily. Organic potting soil, on the other hand, doesn’t contain any dirt. It is peat moss and organic matter, like compost. It’s mostly air, so it drains quickly and needs to be watered frequently. (The non-organic versions can include the abovementioned minerals and even Styrofoam to give it more aeration.)
Paper Towels or Newspapers
Paper towels and newspapers are great, low-maintenance options. It is easy to see when your pet has gone to the bathroom (a clear indicator that they are eating), and they can be replaced easily.
These disposable paper products benefit younger cresties, who are more likely to accidentally eat loose substrate while hunting dubia roaches.
Some keepers avoid them because they need to be replaced often. Compared to moss and coconut bedding, they don’t hold moisture well. Lastly, they don’t look as natural as the other top-performing options.
No Substrate
One final option is to not put anything down on the bottom of the tank. The keepers who do this avoid any ingestion risk and any mess from natural products.
If you go this route, you must clean it daily. A humid environment is harder to maintain, and water might pool on the bottom of the tank as the droplets run down the sides.
Substrates to Avoid
Cypress Mulch
Mulched wood from the cypress tree is a staple form of bedding. It has large, dense fibers and retains moisture. It is lightweight and easy to clean, so keeping the enclosure looking and smelling fresh doesn’t take much effort. It is inexpensive compared to other options (like coconut fiber).
Unfortunately, this choice of substrate is not suitable for crested gecko enclosures. Depending on the quality, it might have sharp pieces. If the pieces of wood are too big and accidentally eaten, it creates a risk of impaction.
Zoo Med’s Forest Floor Bedding, a 100% natural cypress mulch substrate, is an excellent product for other forest-dwelling species.
Wood Shavings
Wood chips have become increasingly popular as bedding for reptiles, but they are not a good fit for crested geckos. While it looks good and is easy to keep the cage clean and comfortable, each type has a downside.
Pine and cedar shavings have toxic oils, which can lead to health issues. When you recognize that cresties are prone to mistakenly swallowing the ground, these oils are even more dangerous.
While not toxic, aspen shavings aren’t much better. They are made for desert snakes and lizards. The size and shape of the pieces make them easy to swallow while hunting insects.
It is better to look elsewhere for solutions for cresties.
Reptile Carpet
Reptile carpets are made from recycled plastic and come in various colors. While they do not carry any risk of impaction and are inexpensive, they don’t hold moisture well. They are treated to prevent leaks, but fungus and bacteria are more common due to the high humidity needed in tropical terrariums.
Some keepers report having the fibers getting caught on the toe pads.
Much like the other options in this section, pieces of carpet are a good choice for different breeds, just not this one.
Bioactive Substrate
Many products on the market say they offer the perfect substrate for a bioactive habitat. In reality, there is more than one blend that will work.
A bioactive environment doesn’t call for a uniform bedding material found in nature. Complex systems in larger enclosures work better as different organisms find their place. Beneficial bacteria, fungi, and tiny invertebrates each need something slightly different, and they all work together to make a fully-working microcosm.
Years ago, in the early stages of hobbyists setting up larger tanks for crested geckos, there was lots of experimentation with special substrate mixtures. One of the first formulas to gain success used shredded orchid bark over a drainage layer. That was covered with a thin layer of coconut shavings followed by dried thick leaves from a magnolia or oak trees. It worked well but could have been better. The soil mixture tended to dry out, and the water collected at the tank’s bottom needed to be drained often.
Today, many recipes for DIY bioactive soil substrates and professionally blended commercial products exist. When selecting one, look for one that uses 40-50% potting soil, roughly 30% coconut, and a combination of elements that drain well (like sand, orchid bark, and cypress mulch). This combination should be able to hold water so that if it is squeezed, it keeps its shape, but that water still passes through it.
Conclusion
Learning about and selecting the perfect substrate for your crested gecko vivarium is worth the time and effort.
A good base will help sustain a humid habitat, be comfortable and safe for them to walk on, and not create cleaning headaches for you. Avoid anything with potentially toxic chemicals or that poses an ingestion risk.
With the correct type of substrate, you’ll be able to keep your pet lizard happy and healthy for years to come. A suitable reptile substrate will go a long way towards a healthy crested gecko habitat and improved quality of life!
