Getting the best substrate for tarantulas means you’d have to experiment with various substrates. When I first bought my first T about five years ago, the popular choice for spider bedding was dry vermiculite.
But a lot has changed since that time, and better (and more appropriate) options are now recommended.
If you ask a group of tarantula keepers what material they choose to keep their prized pets on, you’d most likely get a variety of responses.
One time, a survey was carried out, and it was discovered that there are a wide range of choices that tarantula keepers mix and match to get the properties they desire.
6 Of The Best Substrate For Tarantulas
Much is up to personal choice, and I really do find it quite fun to experiment with various combinations. What follows is a list of some of the more popular choices as well as some pros and cons of each.
Coco Fiber (Eco Earth)
The bags will save you the effort to re-hydrate the compressed bricks, but they are more pricey.
Zoo Med’s Eco Earth is probably the most well-known brand, but other companies also produce the bricks (and some are great plus less expensive).
- Ability to resist mold.
- Great when used dry for arid enclosures.
- Fairly inexpensive if you purchase it in bricks. Buying bricks in three packs makes it even more affordable.
- Absorbs water well for species that need some moisture.
- It can turn out to be quite expensive when filling larger enclosures.
- Dries out quickly (could be positive with arid species)
- Re-hydrating coco fiber has to be dried out before being used in an arid enclosure (I put mine in a large foil turkey pan, then slowly bake it in an oven at about 250°, watching it at all times)
- When dry, it can be “fluffy” and more difficult for burrowing species to create homes.
This regular run-of-the-mill topsoil can be a great and inexpensive substrate choice. It can be bought at Amazon, Walmart, Home Depot, or Lowe’s in large bags for only a couple of dollars.
If using topsoil, it’s important to make sure that it’s organic with no fertilizers added (this includes animal waste). I have found myself using topsoil mixes more and more due to the cost-effectiveness, availability, and water-retaining qualities.
It should also be noted that many European hobbyists who keep Cute T have been using regular topsoil from their yards for years with no ill effects.
- Very Affordable
- It can be easily bought.
- Mixes well with other substrates to get desired properties.
- Packs down well; good for burrowing species.
- Inconsistent quality. Often comes with jagged chunks of wood chips and branches that must be filtered out.
- Very heavy when used to fill larger enclosures.
- If used straight up, moistening/spraying of the substrate can create puddles or mud. It does not absorb water as well as other substrates.
Vermiculite & Perlite (As an additive)
For species requiring more moisture, I put a 1/2″ thick layer of vermiculite on the very bottom of the enclosure, then mix some in with the 50/50 coco/peat combination and fill the rest of it.
I discovered that the vermiculite retains water better than peat or coco alone and allows for better water percolation.
This allows any water I pour in to filter down to the bottom, keeping the lower levels humid and moist like the tarantula’s burrow in the wild.
For Ts requiring more humidity, this also allows the water to evaporate more slowly, elevating the humidity inside the enclosure as it does.
Be careful here, so you don’t add too much water, as overdoing it keeps the soil “fluffy” and prevents it from being packed down well. Vermiculite is relatively inexpensive, and I always keep some on hand.
- Very light
- Absorbs plenty water
- Rarely if ever, attracts mould
- Freely available from garden centers
- Looks pretty unsightly
- Some tarantulas don’t seem to like it.
Just like the topsoil, you want to go with a product that is organic and contains no fertilizers.
- It is absorbent when wet down for species requiring moisture.
- Mixes well with other substrates
- Very inexpensive and comes in large quantities
- Packs and forms very well for burrowing species
- It can prove to be a bit dusty if used dry.
- Like topsoil, the quality from bag to the bag can vary. Large sticks or chunks must be filtered out.
- Can be prone to growing fungus or mold.
As earlier stated, these three are top choices amongst enthusiasts when it comes to the best substrate for tarantulas, and each can be used alone, or they can be mixed and matched to create a substrate to fit any need.
For most of my enclosures, I’ve been using a 50/50 mix of coco fiber and peat moss. This has become my “all-purpose” substrate for many of my specimens.
Moss absorbs water like a sponge and holds onto it quite well. When used inside an enclosure, it can be wet down to provide a source of humidity. I like to place some around water bowls to soak up the overflow.
Although reptile supply companies produce different mosses, clean organic horticultural moss can also be purchased at Walmart, Home Depot, Lowe’s, and gardening supply stores.
Bad Tarantula Substrates
So, now that the winners have been picked.
Let look at the list of the bad choice substrate to you. Although it would be impossible ever to list every bad choice of substrate, it does make sense to list some of the more common suggestions seen so that you can understand why they should be avoided.
- Bark Chips
Bark chips come in a range of forms. There are lighter chippings such as beech, which is widely popular among snake keepers, and there are fine dark chipping often sold as “rainforest bark” in reptile shops, and there are lighter chippings such as beech, which is popular among snake keepers.
All of these options, though, have many weaknesses. Not only do they lack moisture absorption abilities. They’re also likely to go moldy and start rotting in the warm and humid environment that tarantulas need.
Added to that, they aren’t ideal for burrowing; these substrates generally have very little application for tarantula keepers.
- Corn Cob Granules
Corn Cob granules may be eco-friendly and popular amongst popular reptile owners with desert-type reptiles. Still, these granules tend to rapidly go moldy and need to be constantly removed and replaced. Not an ideal substrate (according to reviews and my experience).
Sand isn’t the worst substrate out there, but it isn’t amongst the best substrate for tarantulas and tends to be very heavy, and doesn’t make for very good water retention.
Tarantulas seem to have a thing against gravel and spend much time and energy trying to climb up the walls of their cage away from it.
This can cause harm and pain if the spider falls, so it should be avoided.
While it doesn’t tend to go moldy for obvious reasons, it is next to hopeless for retaining moisture in the cage and thus does not make a top-best burrowing tarantula substrate.
Conclusion: What Is the Best Tarantula Substrate?
Personally, after keeping hundreds of tarantulas over the years, I believe the very best substrate for tarantulas is coir.
It is flexible, light, excellent at retaining moisture, and looks great. As a second choice, I would go for potting compost combined with some vermiculite to retain moisture (3:1 ratio or thereabouts).
In addition, I often (but not always) use small amounts of moss to decorate the cage as I’m very into naturalistic setups for my exotic pets.
Nothing makes my pets happier than buying them a new Exo Terra and spend some hours with bags of moss, wood, bark, and so on to turn it into the semblance of a tropical rainforest.
So, there you have the list of 6 of the best substrate for tarantulas you can buy your pet now.