Bentonite and friends for humid environments?

[Vermis]

Prodded by RezonantVoid's thread about clay substrates for trapdoor spiders, I wanted to try and give my G. iheringi something a little more substantial to dig into than coir. She's never complained, and I've read how they're not enthusiastic burrowers anyway, but still.
Lack of 'wild' clay options that haven't been thoroughly fertilised turned my attention towards other types and sources, like bentonite, or what I managed to get my hands on: sepiolite. It's a similar sort of silicate clay, used for cat litter, liquid spills, etc. For the purposes of this topic I assume they behave the same in substrate setups

So now that I have it, what do I do with it?

It's in granular form, like cat litter. I've searched for mentions of clay and bentonite here on AB, and scared up a couple of mentions of crushing it to dust before wetting and mixing it. Is that strictly necessary, or can it be wetted and mixed with other substrate constituents as is? Would wetting it help to break it down? I.e. softening it and reducing dust, hopefully.

Most references to bentonite that I find here involve dry burrowing substrates for desert scorpions. No more than 3-4% mixed with play sand to avoid turning the mixture rock-hard, and to save scratching the scorp's exoskeleton. What if I bucked the trend for dry T substrates and kept it a little moist? (proper ventilation, add clean up crews, etc. etc.) I've seen one recipe for about 25% bentonite, mixed with coir and sand. Any misgivings about going higher?

 

[Frogdaddy]

Try searching the dart frog forum Dendroboards. There should be some info there as dart frog hobbyists have been making clay backgrounds for years. I believe straight cheap unscented kitty litter was the product of choice.

 

[Vermis]

Man, is dendroboards still going too? Excellent. I'll have a look there, thanks.

@Frogdaddy what a rabbit hole you sent me down. Sodium bentonite vs. Calcium bentonite, CECs, iron oxides, microfaunal habitats...

Although, since a lot of it has to do with maintaining a bioactive environment, I don't think I need to put that much thought into it for Ts. Fortunately! Nevertheless, what I've read has given me some interesting pointers towards 'artificial soil' and crumb texture. I've gathered my main ingredients - sepiolite, coir, play sand - and a few small pots. I'll try out a few mixes in different proportions: see what I can wet, pack down, and dry out, while keeping a better structure than loose dust or a hard, cracked lump.

 

[Frogdaddy]

Yeah there is some good stuff out there.
I'm interested in hearing about your results worth the different mixes. Hopefully you can come up with something that has the feel and structural integrity of clay without the weight of clay.

 

[AphonopelmaTX]

The clay soil @RezonantVoid refers to in his non-tarantula mygale thread is also referred to as 'loam'. Loamy soil has clay content in various percentages, but it is not 100% clay. The majority of potting soils, or top soils, sold in garden centers (at least in America) has some clay content and can be classified as a loamy soil. Besides, too much clay content and a tarantula that likes it more on the dry side will not be able to burrow in it. There really is no need to experiment with all of these strange mixtures of inorganic compounds when a bag of plain old dirt will do the same thing. Just my two cents anyway.

 

[RezonantVoid]

The clay soil @RezonantVoid refers to in his non-tarantula mygale thread is also referred to as 'loam'. Loamy soil has clay content in various percentages, but it is not 100% clay. The majority of potting soils, or top soils, sold in garden centers (at least in America) has some clay content and can be classified as a loamy soil. Besides, too much clay content and a tarantula that likes it more on the dry side will not be able to burrow in it. There really is no need to experiment with all of these strange mixtures of inorganic compounds when a bag of plain old dirt will do the same thing. Just my two cents anyway.

Correct, natural loam mix (with high clay content) is IMO/E the almost universal best method for housing stuff as it can turned into a massive variety of consistencies and textures using pretty much just a bit if extra sand, peat and water. My agenda for husbandry has always been "just because something works doesn't mean it can't be improved upon". At least from my perspective, the definitive opposite of this viewpoint has applied to substrate for a LONG time, with the majority of people seeming to just use the easiest and cheapest method that works for them. I do not believe in dry, crumbly mixes for every single terrestrial/fossorial, I do not believe in using cork bark for every arboreal, and I don't believe in substituting natural decor with fake ones. I'd much rather research extensively something's natural habitat, and go the extra mile to make a permanent enclosure that the spider doesn't tear up every 4 months making a new burrow in. This is not an attack on the general hobby, just the approach I take to husbandry.

@Vermis , I do commend you for wanting to branch out and have a crack at upgrading your T's substrate. I don't believe the brand or mineral matters as much as the end consistency does, so I'm sure sepiolite would work. For prepping it, it again comes down to what the invert your housing on it lives in. For the majority of my collection, clay alone is too sticky and tough, so I moisten in and dry it using reptile sand and peat to make it more dry and pasty. This allows them to construct the lids they build effectively but without it sticking to their fangs and chelicerae, and ill adjust the ratios marginally genus to genus, species to species. Also, if your stuff is already dry and powdered, you can mix it straight away with whatever you need such as sand or peat instead of the hydrating and drying process I use before hand on wild clay.

But I'm not sure what environment G.iheringi naturally occurs in. It may be that clay based substrate doesn't suit them at all, and a much more sandy mix is what they prefer. Perhaps you can make test batches in a temporary container and seeing what your spider settles the best into

 

[AphonopelmaTX]

Correct, natural loam mix (with high clay content) is IMO/E the almost universal best method for housing stuff as it can turned into a massive variety of consistencies and textures using pretty much just a bit if extra sand, peat and water. My agenda for husbandry has always been "just because something works doesn't mean it can't be improved upon". At least from my perspective, the definitive opposite of this viewpoint has applied to substrate for a LONG time, with the majority of people seeming to just use the easiest and cheapest method that works for them. I do not believe in dry, crumbly mixes for every single terrestrial/fossorial, I do not believe in using cork bark for every arboreal, and I don't believe in substituting natural decor with fake ones. I'd much rather research extensively something's natural habitat, and go the extra mile to make a permanent enclosure that the spider doesn't tear up every 4 months making a new burrow in. This is not an attack on the general hobby, just the approach I take to husbandry.

@Vermis , I do commend you for wanting to branch out and have a crack at upgrading your T's substrate. I don't believe the brand or mineral matters as much as the end consistency does, so I'm sure sepiolite would work. For prepping it, it again comes down to what the invert your housing on it lives in. For the majority of my collection, clay alone is too sticky and tough, so I moisten in and dry it using reptile sand and peat to make it more dry and pasty. This allows them to construct the lids they build effectively but without it sticking to their fangs and chelicerae, and ill adjust the ratios marginally genus to genus, species to species. Also, if your stuff is already dry and powdered, you can mix it straight away with whatever you need such as sand or peat instead of the hydrating and drying process I use before hand on wild clay.

But I'm not sure what environment G.iheringi naturally occurs in. It may be that clay based substrate doesn't suit them at all, and a much more sandy mix is what they prefer. Perhaps you can make test batches in a temporary container and seeing what your spider settles the best into

Let me first start by saying "been there, done that". Since tarantulas occur within a short drive of where I live, I am able to examine the soils they live in. In north Texas, we have a soil high in clay content which the tarantulas burrow in. I thought to myself, "since they burrow in clay soil in the wild, maybe they will in captivity." They did not, at least, not without a pre-made burrow.

The hypothesis I formed as to why tarantulas don't burrow in clay soils in captivity compared to the wild is that there is a matter of energy cost vs. need. In captivity, there are temperature controls, no precipitation, no predators, and due to the large size of tarantulas compared to other spiders, the tanks are fairly small in relation to their size. Clay soils are hard to dig in when dry so in nature, a tarantula can only really dig in it when it is wet. This poses a problem in captivity for a number of species which come from dry areas. If the soil is damp, the tarantula will most likely climb to the top of its cage and stay there until it is dry. By then, the clay soil will be too hard to dig in. If a tarantula is perfectly content in its cage, it will make no effort to expend the energy to dig in a hardened soil. Therefore, if it has no need to burrow in soft damp soil, or hardened dry soil, it won't.

This is an interesting contradiction to the wild Texas tarantulas I find. When it rains, and the soil becomes wet, tarantulas don't abandon their burrows and climb a tree; they seal them up and sit in a wet burrow. If a tarantula has left its burrow for any reason, and can't dig a new one when the soil is dry and hardened, presumably, it will find some kind of shelter to hide under until the soil becomes damp again. Or it will find something to burrow under and expend the energy to get out of sight. Texas tarantulas make their own burrow and adapt to pre-existing structures so it is hard to tell what they are doing sometimes. In the wild, there is a strong need to burrow in the clay soil and stay there no matter what. I think it is obvious as to why.

There are tarantulas that will acclimate to clay soils which are the obligate burrowers. Those don't seem to care what kind of soil is used so long as they can dig in it, but even they won't, or can't, dig in dry hardened clay soil. The tropical obligate burrowers could benefit from a damp clay soil since the burrows need to retain their shape to avoid collapses as they practically dig out the entire bottom of the cage. Spiderlings of most tarantula species fall into the obligate burrower category, but as they grow the ratio of cage size to body size starts dropping and they appear to feel safe in the cage without needing to create their own hideout. In other words, the cage itself becomes a suitable burrow.

This is why a more unnatural soft soil is needed for captive tarantulas. If they don't have to put too much effort into digging, a tarantula will be more likely do so. But of course, I don't expect anyone to take my word for it. One should always experiment and draw their own conclusions.

 

[Vermis]

Finding a substrate with the consistency but not the weight of clay might be a bit optimistic! I don't hope to hit on something miraculous or to wow veteran spider keepers, just to goldilocks something that my spider (and future spiders) might be comfortable on. And in.

There really is no need to experiment with all of these strange mixtures of inorganic compounds when a bag of plain old dirt will do the same thing.

True, true! I've been looking at bags of topsoil - and even Pets at Home's 'tortoise terrain' - thinking "well why don't I just get that?" Difference being the bag of topsoil will cost me at least £5 (and a spin on a roulette wheel, according to online reviews) and the strange inorganic compound cost me £0.

Plus, I'm curious. But rest assured, if I don't manage to concoct anything that the spider or I like, Westland will be seeing some of the contents of my wallet.

Also, if your stuff is already dry and powdered, you can mix it straight away with whatever you need such as sand or peat instead of the hydrating and drying process I use before hand on wild clay.

It comes as granules. I thought damping it might help it break up some more during mixing, or encourage finer particles to slough off and properly act as a binder. But 'dry' can be one or two of my test pots.

But I'm not sure what environment G.iheringi naturally occurs in. It may be that clay based substrate doesn't suit them at all, and a much more sandy mix is what they prefer. Perhaps you can make test batches in a temporary container and seeing what your spider settles the best into

Yup! I've been trying to look up info about where G. iheringi has been found or reported, but my google-fu might be a bit weak. This page about Uruguay was most helpful, so far. Humid subtropical, verging on temperate, decent rainfall but not sopping wet. Rolling grasslands and productive agriculture. A quote about the soil:

Soils are mostly of the dark brown to black color type, of medium depth, favourable soil properties and medium high nutrient content (generally with P deficiency)

That makes me assume it leans towards rich and loamy, rather than the extremes of sandy or thick clay. (Shoot, talk about Goldilocks...) But I'm no expert. There are links to much more detailed soil analyses, but they're in Spanish, and the built in Google translater is giving me grief. A trip to Bing might be in order.

But I'll keep looking for other info, too. Thanks all, much to consider.

 

[liquidfluidity]

Try searching the dart frog forum Dendroboards. There should be some info there as dart frog hobbyists have been making clay backgrounds for years. I believe straight cheap unscented kitty litter was the product of choice.

This is true. I recently watched Reptiliatus create a set up using kitty litter. Turned out really well for his purposes. Seemed to dry hard as he was creating a substrate dam and a water feature.

Yes, Dendroboards is still going. I actually recently joined as my desire to build a sweet terrarium for a few of my girls has grown. Seems to be some talk of using Bentonite in a few of my last reads there.

 

[Nocebo75]

There are links to much more detailed soil analyses, but they're in Spanish, and the built in Google translater is giving me grief

I'll be happy to help if I can, but we may have the opposite problem My mother tongue is Spanish, not English, so I cannot guarantee I'll be able to translate accurately to English, especially if it's very technical terminology.

But happy to give it a go if you point me to the parts that are causing you trouble.