A couple years ago a young tenant left a box of reptile supplies in my father-in-law’s garage when she moved out of the triplex he owns. He wanted to know if I could use any of it.

I stood there shaking my head as he held out a bag of walnut shell branded as reptile substrate.

“Do you know what the boys in our neighborhood used walnut shells for when we lived in Arkansas?” I asked.

“No idea,” he replied.

“They’d throw them in the water and come back in the morning to pick up all the fish.”

It’s true. Walnut trees contain a toxic substance called juglone, which kills off competing plants. When thrown in the water it can also kill fish.

So would YOU knowingly expose your reptiles to fish toxin?

I thought not.

I don’t know what walnut shells are actually good for, but it’s not reptile substrate. Sure, some people use it with no problem, but is it worth the risk? Don’t do it!

Now that my rant is out of the way, let’s dig in to the topic of this blog: the “Great Reptile Substrate Debate!”

As a reptile owner, you know how important it is to create a comfortable and enriching environment for your cold-blooded companions. But with a plethora of substrate options available, choosing the right bedding for your reptile’s enclosure can feel overwhelming.

Never fear! This blog post dives deep into the pros and cons of various substrates, so you can make an informed decision that will keep your critters happy and safe.

Understanding Reptile Substrate

Substrate, or bedding, lines the bottom of a reptile’s enclosure and plays a vital role. Reptile substrate mimics their natural habitat, provides opportunities for natural behaviors like burrowing and hiding, and helps maintain appropriate humidity levels.

But buyer beware! Not all substrates are created equal. Here’s a breakdown of some popular options:

  • Loose Substrate:
    • Pros: Provides a natural environment that encourages digging and burrowing behaviors. Some loose substrates, like coconut fiber (coir) and cypress mulch, hold moisture well, which is beneficial for species with higher humidity requirements like leopard geckos, any amphibian, or ackie monitors.
    • Cons: By now you know to avoid walnut shell substrate, even if it comes with a picture of a bearded dragon on the bag. But even non-toxic substrates can pose a risk of impaction if ingested, especially in young reptiles. Loose substrates can be messy and require spot cleaning as well as regular full enclosure cleanouts. Dusty loose substrates, like some sand varieties, can irritate your reptile’s respiratory system.
  • Paper Towels or Reptile Carpet:
    • Pros: Easy to clean and hygienic, these reptile substrates are a popular choice for hatchlings and quarantined reptiles. Paper towels are readily available and disposable, simplifying cleaning routines. Reptile carpets offer a textured surface that provides some grip for your reptile.
    • Cons: Lack the natural feel and enrichment of loose substrates. Paper towels offer minimal to no moisture retention, making them unsuitable for high-humidity environments. Reptile carpets can harbor bacteria and become difficult to clean thoroughly over time, potentially leading to hygiene issues.
  • Ceramic Tile or Slate:
    • Pros: Solid, easy to clean, and aesthetically pleasing. These substrates are ideal for visual predators who might stress from seeing their reflection through glass enclosures. They are non-porous and resistant to mold growth, making them a good choice for environments with fluctuating humidity levels.
    • Cons: Don’t provide any environmental stimulation or burrowing opportunities. The hard surface can be uncomfortable for some reptile species and may cause joint problems. Ceramic tile can get quite cold, requiring additional heat sources to maintain proper thermal gradients within the enclosure.
  • Reptile-Safe Sand:
    • Pros: Mimics the natural habitat of desert reptile species and provides a visually appealing arid landscape. Some commercially available reptile sands are formulated to be clumping, making spot cleaning easier.
    • Cons: Can cause impaction if ingested, especially in young reptiles. Sand can be difficult to clean thoroughly, potentially harboring bacteria. Loose sand particles can irritate your reptile’s eyes and respiratory system.
turtles on reptile carpet

Choosing the Right Substrate: Tailoring to Your Reptile’s Needs

The key to choosing the right substrate lies in understanding your reptile’s specific needs. Here are some key factors to consider when choosing a reptile substrate:

  • Species: Different reptile species require vastly different environments. Bearded dragons, for example, thrive in arid environments with paper towels or tile substrates. Leopard geckos, on the other hand, benefit from the burrowing enrichment offered by coconut fiber or a bioactive reptile substrate mix. Research your specific reptile species to understand their natural habitat and preferred humidity levels.
  • Age: Young reptiles are more prone to ingesting substrate accidentally. Opt for paper towels or tile for hatchlings and juveniles to minimize the risk of impaction. As your reptile matures, you can consider introducing loose reptile substrates like coconut fiber or a bioactive mix.
  • Humidity: Some substrates excel at retaining moisture, which can be beneficial for tropical or rainforest species that require higher humidity levels. Coconut fiber, for instance, offers excellent moisture retention. Conversely, desert-dwelling reptiles like bearded dragons require very low humidity levels. Paper towels or tile are ideal for these species as they don’t trap moisture.

Beyond the Basics: Exploring Bioactive Substrates

Bioactive substrates are a relatively new but increasingly popular option. These pre-mixed concoctions often contain a blend of coconut fiber, sterilized soil, and beneficial isopods and springtails. Bioactive reptile substrates create a miniaturized ecosystem within the enclosure, mimicking the natural breakdown of waste products by these tiny detritivores.

  • Pros: Bioactive substrates promote a more natural environment, encouraging beneficial bacterial growth and breaking down waste products. This can help maintain a clean and odor-free enclosure, reducing cleaning frequency. Some bioactive substrates offer excellent moisture retention, making them suitable for species with moderate humidity needs.
  • Cons: Bioactive reptile substrates require a healthy population of isopods and springtails to function effectively. These detritivores may not be readily available in all pet stores, and maintaining their population can be an additional responsibility.

Remember: When in doubt, consult a reptile expert or veterinarian for personalized advice on choosing the best substrate for your reptile.

Happy Herping!

By understanding the different substrate options and your reptile’s specific needs, you can create a healthy and enriching environment for your scaly friend. With proper care, your reptile can thrive for years to come!

👉Don’t forget to share this post with other reptile enthusiasts to help them navigate the great substrate debate!