Best Terrarium Substrate for Tarantula Enclosures – 2022 Guide

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Looking for the best terrarium substrate for your tarantula enclosure? Then this guide is for you!

Here we have 5 top-rated terrarium substrates that work best for burrowing and non-burrowing tarantulas.

Most tarantula experts recommend coconut fiber, peat moss, potting soil mixes, and vermiculite as top choices in substrates.

Based on these, here are 5 best terrarium substrates for tarantula enclosures:

Our Editor’s Pick: Zoo Med Eco Earth Loose Coconut Fiber Substrate$7.29Buy Now
Best Overall: The Bio Dude Terra Aranea BioActive Substrate for Tarantulas$19.95Buy Now
Best Budget: Zoo Med 100% Natural Cypress Mulch$6.81Buy Now
Best Soft Substrate for Burrowing Tarantulas Josh’s Frogs Dig-It$17.99Buy Now
Best for Terrestrial and Arboreal: Critter’s Comfort Arachnid Habitat Substrate$9.00Buy Now

Best Terrarium Substrate – 2021 Top 5 Picks

1. Our Editor’s Pick: Zoo Med Eco Earth Loose Coconut Fiber Substrate

Thousands of positive reviews about Zoo Med Coco Fiber Substrate makes it one of our favorites.

In addition to using it as a terrarium substrate for tarantulas, you can also use it for reptiles, amphibians, insects, and mollusks enclosures.

Eco-Earth substrate also expands to create 7 to 8 liters of substrate making it ideal for tanks measuring 16 x 16 x 20 inches or larger.

This green and ecofriendly substrate also breaks downs odors and waste products and remains optimally damp while resisting mold and mildew. You can also use it dry if your species of tarantulas are from the desert areas.


  • Versatile
  • Ideal substrate for most tarantulas
  • Value for money
  • Well-packaged
  • Easy to clean
  • Great scent


  • Some bags had mites
  • Dried substrate tends to scatter and make a mess

2. Best Overall: The Bio Dude Terra Aranea BioActive Substrate for Tarantulas

Four features of the Bio Dude Terra Aranea Bioactive Substrate make it ideal for burrowing and non-burrowing tarantulas:

One, it retains its shape so your pets can hide, burrow, molt, or dig under it.

Two: it is long-lasting. The brand promises an IO-balance that makes the substrate ecofriendly and can even last the lifetime of your pet.

Thirdly, Bio Dude Terra Aranea Bioactive Substrate ensures clog-free and stagnation-free drainage and aeration.

Last but not the least, it promises to maintain humidity and water balance in the middle and bottom layers whilst keeping the top layer dry.


  • Stays dry on the top and moist below
  • Retains burrows and shapes
  • Thoroughly tested for over a year


  • A larger tank of 5.5 gallons would need at least one 6-quart bag and one 3-quart bags. This could be expensive.

3. Best Budget: Zoo Med 100% Natural Cypress Mulch

Zoo Med Forest Bedding with 100% natural Cypress mulch is economical and affordable. This green product is also suitable for snakes, lizards, insects, and other small animals.

Also, the natural forest floor retains moisture and humidity to keep your pets thriving.

It also comes in different sizes so you can easily fill a 4 x 2 tank twice with the substrate depending on how deep you want it. (An 8-liter bag covered a 1-gallon aquarium at least 3-4 times!)

Some people suggest boiling the mulch before use – this helps eliminate mold, mites, etc. You could even bake it but sometimes, baking tends to degrade it.


  • Long lasting
  • Affordable
  • Versatile


  • Bugs and mites reported
  • Very dusty

4. Best Soft Substrate for Burrowing Tarantulas Josh’s Frogs Dig-It

Josh’s Frog substrate consists of soft, moisture-retaining mixture of peat moss and vermiculite.

This makes it ideal for burrowing tarantulas. It also retains moisture but can also be kept dry for the arid species. This makes Josh’s Frogs Dig-It substrate ideal for geckos, lizards, frogs, and spiders.


  • Super stretchable and long lasting
  • Thick
  • No dead bugs
  • Value for money


  • Slight odor.

5. Best for Terrestrial and Arboreal: Critter’s Comfort Arachnid Habitat Substrate

Your tarantulas will feel right at home in this all-natural substrate from Critter’s Comfort Company. It holds its structure well making it ideal for burrowing and terrestrial tarantulas. Your critters will be able to move easily through this soft substrate.

Being all-natural, there are no strong chemical smells to deal with. Also, the substrate resists mold, mildew, and fungal growth.

The best part is the substrate’s ability to hold moisture through its layers and you can also rehydrate it easily through daily spraying or misting.


  • Excellent for a variety of terrestrial, burrowing, and arboreal species
  • Optimal for egg incubation as well.
  • Holds structure and shape
  • Retains moisture
  • Deters fungal growth
  • Odor-free


  • Low quantity for the money you pay.

How To Select Tarantula Enclosure Substrate

Here are the factors to consider when selecting your tarantula enclosure’s substrate:

1. Ideal for your inhabitants

Select a substrate that works best for the species you have. These days, the substrate comes specifically for burrowing, arboreal, terrestrial, and other species.

For example, burrowing tarantulas need softer substrate as it is easy to dig through and can be easily burrowed and made into homes.

On the other hand, your arboreal species of tarantulas will need a forest floor that encourages plant growth so they can build their webs in trees.

Best substrates for tarantulas are coconut fiber, peat moss, vermiculite, corn cob granules, cypress mulch, and potting soil.

Some tarantula keepers also mix one or more of these materials to keep their pets in. This way, your pet can get optimal water retention, aridity, humidity, etc.

2. Size of your enclosure

Before buying your bag of substrate, measure your terrarium enclosure properly. Then decide the depth of the substrate.

Most tarantula species need a substrate of depth of at least 5-inches. This way, your pet can easily dig, burrow, and hide in it. Make sure that, after adding the substrate, your pet has ample space above it from the surface of the substrate to the entrance of the enclosure.

Accordingly, select a bag of substrate of the appropriate size. You could also purchase more than one bag so as to fill up the enclosure to its optimal depth.

3. Retain shape, moisture, and optimum humidity

Look for substrates that can retain their shape. This is especially necessary for burrowing tarantulas.

Also, the substrate should have optimal humidity and aridity. Its inner layers may retain moisture while the top layer can have dryness. This is ideal for tarantulas.

You must also be able to replenish the moisture by spraying the substrate once every few days.

4. Deters bugs and fungus

The last thing you want is your substrate to develop fungus, mold, and mildew. So look for natural materials that deter these problems. Also, look for substrates that are free from gnat eggs. If needed, bake or boil the substrate before adding it in.

5. Odor-free

Natural substrates usually are free from chemicals which makes them keep odors at bay.

6. Low dust

Avoid substrates that crumble and powder or create a mess in the enclosure.

7. Sustainable, natural, and eco-friendly

Green substrates can be grown in a sustainable manner making it easy to replenish. They reduce carbon footprint, degrade easily, and protect our landfills. Look for substrate that is free from chemicals, fungicides, pesticides, etc.

What Substrates Should You Avoid for Tarantula Enclosures?

The substrates to avoid for tarantula enclosures include:


Sand does not retain shape and that makes it not-so-great choice for tarantulas that like to burrow and dig. Also, it can be too soft for tarantulas. However, many expert tarantula keepers sprinkle sand through their coco peat or vermiculite substrates.


Gravel is another bad choice for substrates. Most tarantulas dislike standing or burrowing through gravel. Also, if your pet falls down from the enclosure walls, gravel could hurt its delicate exoskeleton. The same goes for rocks, pebbles, shells, etc.

FAQs on Best Tarantula Substrates

1. Is sand okay for tarantula enclosure to use as substrate?

No. Tarantulas need to burrow and dig. They also need the substrate to hold and retain its shape. That is why, sand is not a good option. Many tarantulas even hate walking on sand.

2. What are the problems with perlite for tarantula substrates?

Perlite can sometimes contain chemicals, fertilizers, etc. However, many substrate manufacturers add perlite to substrates to contain gnats and mold.

3. What properties make coconut fiber great as substrate for tarantula enclosures?

Coconut fiber is 100% natural and eco-friendly. It can be used standalone or mixed with other materials to make substrate for spider enclosures. It is naturally mold-free and bug resistant and also retains shape, moisture, and optimal humidity. Being dry, it is ideal for tarantulas from arid environments.

4. Can mold be bad for tarantulas?

Yes, mold can even kill tarantulas. So, always keep the enclosure well ventilated. Make sure that the substrate is slightly moist but the decorations are dry.

5. Can tarantulas drink from their substrate?

Tarantulas sip water from their water dishes. Some tarantula owners do not provide water dishes in the enclosures so tarantulas can sip water from the substrate. That is why it is important to keep the tarantula substrate misted (but not too damp). Too much dampness can cause many problems.


The best tarantula enclosure or terrarium substrates consist of coconut fiber, potting soil, or peat moss and vermiculite. It is ideal for burrowing and terrestrial as well as arboreal species of tarantulas.

We recommend the Zoo Med Coco Fiber Substrate as it is clean, free from bugs and mold, has a natural, earthy scent, and soft for burrowers. Do check out our other recommendations as well!

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