High Humidity Enclosure for Burrowing Tarantulas

[SuperRad]

Incorporating design elements from false bottom enclosures and those that use live plants I have constructed a high humidity enclosure designed for fossorial species such as Citharischius crawshayi and Hysterocrates gigas. In terms of tarantula terrariums false bottoms are usually reserved for arboreals. Due to the amount of substrate used in an arboreal enclosure the subject of water evaporation was a non issue. Since my set up is for burrowers, I'm concerned about the effectiveness of water evaporation and this enclosure is a test of sorts to see what complications (if any) arise in this scenario.

I'm calling this project a prototype. Several of these elements will be changed and upgraded. If successful, rock out. If not, back to the drawing board. This go around, the main focus was on adding the water and supporting living plants.

Materials used:

10 Gallon Fish Tank (20x10x11}
Frog Moss
Coconut Fiber (used fine fibers for deeper layers and coarser fibers for upper layers)
Sphagnum Moss
Fiberglass Screen
Hydro Balls
Plant
Straw
Water Bottle
Exacto Knife
Scissors
Tape
Flower Pot
Water Dish

 

[SuperRad]

Living Plant/Watering Feature

With high humidity requirements I wanted living plants to be a feature of my enclosure to provide a secondary ambient humidity source. The false bottom being the first. I picked up a generic small palm plant of sorts from a Home Depot (I was already there for moss). It's hearty nature, medium watering requirements, and root structure made me choose this over others available at the time. I plan to replace this with something more appropriate with more research.

I cut the top off of a tall water bottle that had uniform shape to pot the plant in. Leaving the bottom of the bottle in tact I drilled several holes into the bottom to ensure water in this area would drain properly into the false bottom. If you can find tubing that works similarly that's fine too, there was just none available for myself at the time.

Next I took a thick straw from a bubble tea cafe in my area to make a way to add water to the false bottom with out affecting the plant. The straw was ideal because it was cut at an angle so that it would not be flush with the bottom of the bottle. First I cut some screen to cover the flat end of the straw and I taped it down. This will prevent prey items from using this as a hide or getting suck in hard to get to areas. I lined the straw up slightly higher than the lip of the bottle and taped it to the side. I then added a 2” layer of clay hydro balls to assist with plant drainage. The bottle also got a layer of fiberglass screen to seperate the balls from a thin layer of sphagnum moss. Coco fiber and the plant were then filled in the remaining space.

The tube that houses the plant serves 2 purposes. First, it keeps roots out of areas the tarantula may want to burrow in and also makes maintenance for over growth quick and easy. Second, it will allow me to water the plant without soaking the substrate and disturbing any tunnel efforts made by my T's, making them uncomfortable. Below you can see how the plant and the secondary fill tube orient themselves in the final product. You can see the grate for the straw through the plant.

 

[SuperRad]

Substrate and False Bottom

For the false bottom I used clay hydro balls found in the reptile section of my chain LPS. The idea behind these is that they absorb water and slowly release it as well as increase surface area for evaporation. When you first get a bag it's got a fair amount of dust and small debris that you should clear out to keep a cleaner tank. I put a layer of balls into a shallow plant pot dish and covered it with my fiberglass screen.

The silt gets pretty thick, but after the third rinse water started to be clearer, so I stopped there. Given the dimensions of the tank, I felt that using 1” of pellets would offer more than enough water retention.

I fitted 2 lengths of fiberglass screen to match the area of the tank and also cut a hole in one corner to fit the diameter of the water bottle (roughly 3” in diameter). Taking the first length of screen I covered the pellets and inserted my plant leaving a layer 1 pellet thick just under the bottle. I then covered the screen with sphagnum moss to a depth of 1”.

Taking the second length of screen I placed it over the plant and sphagnum layer and placed rocks on it to keep the screen in place. I then added a thin layer of sphagnum enough to cover the screen and rocks.

Here's a shot of all the layers and the plant:

The reasoning behind the dual layer of sphagnum is that if I have a burrower, I wouldn't want him to disturb the moss nearest the balls, nor would I want him pulling up screen. The extra moss and second screen act as a buffer to keep him away from the vital parts. I then filled the rest of the space with coco fibre 8” at it's highest point and 5” at it's lowest allowing for a fair amount of burrowing space. A broken terracota pot hide was stuck in at a downward angle in the deep portion to promote burrowing.

 

[SuperRad]

Humidity

I designed the plant feature to work as a tool to administer water to the false bottom in two ways. The first way is to just pour water into the tube. This waters the plant and drains through the coco/sphagnum/hydro ball layers and into the false bottom. Another way to use this is the straw. Using a turky baster, syringe, or other such tool, you can squirt water down the tube and into the false bottom with out over watering the plant and killing it or promoting root rot. Additonal humidity is provided and retained by the frog moss located at each corner of the terrarium. Before placing it in the enclosure it was rinsed thoroughly and soaked in water over night. After that it was left moist and in indirect sun for 24 hrs.

The last source of major humidity is a large, shallow reptile feeding dish I picked up for the purposes of giving my H. gigas an area to actually play in water.

This set up is designed to work on a water schedule to provide humidity but also give enough time for things to dry out. Since I just set this up I don't know what time frames I'm working with but I'll be cycling moisture between watering the plant, watering the false bottom directly, misting the moss, and dry periods to allow for more complete evaporation.

 

[SuperRad]

Post Script

As I stated previously, this is a prototype, a work in progress. I would like to switch the plant to something that had limited vertical space, a sparse/shallow root system, low light and medium water requirements. Also, the coco fibre may have issues letting the water evaporate effectively, so I might have to change it to a medium that will allow for fast drainage. I'm pleased with my work, but in my head I see several small things that need to be revamped as I gage how workable this system really is. I'll keep you posted on changes I make as well as how things turn out for good or bad over the next few months of testing things out. Any comments, ideas, and suggestions to make this a success would be much appreciated.

Thanks for reading!

 

[clearlysaid]

I would be slightly concerned about her hurting her claws or fangs on the screen mesh. She will most likely dig and dig and dig till she can't dig no more. She might accidentally get hooked onto the mesh or rip a claw out... Moss won't deter her from burrowing to the screen.

I looks really good, though. You shouldn't have a problem keeping the humidity up in there! She's going to love it.

 

[von_z]

I would be slightly concerned about her hurting her claws or fangs on the screen mesh. She will most likely dig and dig and dig till she can't dig no more. She might accidentally get hooked onto the mesh or rip a claw out... Moss won't deter her from burrowing to the screen.

I looks really good, though. You shouldn't have a problem keeping the humidity up in there! She's going to love it.

That is a pretty awesome looking setup! Clearlysaid might be right about the screen though.

 

[spidersrclass]

Nice tank :clap: A lot of thought to put that together, I have question though, doesn't C Crawshayi come from the more drier areas and not so dependant on humidity? :?

 

[saminthemiddle]

Wow, that's a really pretty setup. Does it keep the substrate dry?

I would throw a hygrometer in there as RH might be a bit hard to guestimate if you have dry substrate.

As an alternative to the screen and those ball things why not try some volcanic rock? The stuff is very porous so I would imagine that it retains water really well and you can get pieces that are big enough that the spider won't excavate them.

 

[Nich]

Nice tank :clap: A lot of thought to put that together, I have question though, doesn't C Crawshayi come from the more drier areas and not so dependant on humidity? :?

The surface yea, but considering the depth of thier burrows in the wild it would be very humid after a few feet down.
A good 8-12" burrow also provides very nice humidity.

 

[saminthemiddle]

Nich has a point, the borrows would be more humid than the surface.

Might this encourage some high-humidity burrowers to burrow and stay burrowed for more time than they would otherwise spend?

 

[Alonso99]

Nice tank :clap: A lot of thought to put that together, I have question though, doesn't C Crawshayi come from the more drier areas and not so dependant on humidity? :?

That is a pretty old misconception. Their burrows tend to have relevant humidity. Keeping these Ts too dry ends up with them losing their big legs. Cool setup.

 

[Moltar]

Cool setup but I have a few comments that may help with your 'production' model.

Firstly I don't think it's really deep enough to offer some of the bigger burrowers the sort of depth they like. That will result in them really trying to dig up the bottom layer. Perhaps you could find a way to make it sturdier? Also if you did it in a taller tank you could have more diggable substrate in there. I have a feeling that a strong, industrious t like crawshayi or gigas will trash both the bottom layer and the plant. the only way to find out is to see what yours does.

If you did this setup with considerably deeper substrate (say, 12") and less surface area do you think the humidity benefits would still be present on the surface?

 

[JMoran1097]

I would be slightly concerned about her hurting her claws or fangs on the screen mesh. She will most likely dig and dig and dig till she can't dig no more. She might accidentally get hooked onto the mesh or rip a claw out... Moss won't deter her from burrowing to the screen.

hahahaha and there goes THIS idea.

 

[Moltar]

hahahaha and there goes THIS idea.

Maybe if he did away with the screen altogether and let the pellets and water discourage her from digging further? Perhaps also the screen could be replaced with some plexi with lots and lots of holes?

 

[clearlysaid]

Knowing my H gigases... the water won't deter them and even the clay pellets. I could totally see mine carrying them up to the surface w/ her as she's clearing her burrow out. The Plexi glass thing, if a feasible idea for still using the false bottom, would be better than nothing or the screen.

 

[SuperRad]

Thank You!

I would be slightly concerned about her hurting her claws or fangs on the screen mesh. She will most likely dig and dig and dig till she can't dig no more. She might accidentally get hooked onto the mesh or rip a claw out... Moss won't deter her from burrowing to the screen.

Drilling plexi isn't really an option for me due to a lack of work space and tools. The thought crossed my mind to do some kind of "thatch work" using thin stripps of some kind of safe wood like mahogany. The sphagnum would assist in retarding the growth of mold (which is why the sphagnum is there anyway) in the wood, but I'm not sure if it would completely eliminate the issue.

What about screen with wider holes or some kind of grate? I have some stuff at home I'll take pix of and post up for opinions when I'm around a cam. I'm receptive to ideas for a different kind of false bottom cover, but I'm just not sure what yet.

Firstly I don't think it's really deep enough to offer some of the bigger burrowers the sort of depth they like. That will result in them really trying to dig up the bottom layer. Perhaps you could find a way to make it sturdier? Also if you did it in a taller tank you could have more diggable substrate in there. I have a feeling that a strong, industrious t like crawshayi or gigas will trash both the bottom layer and the plant. the only way to find out is to see what yours does.

If you did this setup with considerably deeper substrate (say, 12") and less surface area do you think the humidity benefits would still be present on the surface?

The depths in my tank are 8" at the peak, 6.5"ish for the middle areas (both take up the left hand 1/3 of the enclosure) and 5" for the flat part of the tank. I agreee I need more sub and could probably elevate the flat parts to match the 6.5"ish. I agree eventually she needs to be moved to something larger, but that's when I can afford a larger aquarium too.

Wow, that's a really pretty setup. Does it keep the substrate dry?

As an alternative to the screen and those ball things why not try some volcanic rock? The stuff is very porous so I would imagine that it retains water really well and you can get pieces that are big enough that the spider won't excavate them.

This sounds like a pretty good idea. I like the fact that it's a larger option than the clay balls. I'm not entirely sure about the water retention qualities of lava rock though (for some reason I don't think it is that great) but I'll do some research. Lava rock is full of porous little holes too. I'd imagine that the T could get a tarsal claw stuck in those almost as easy as screen.

I'm still going to need a barrier between the substrate and the false bottom regardless of what I'm putting in there (pellets, lava rocks, etc) to keep coco fiber from touching the false bottom and wicking too much moisture into the substrate and also the barrier will keep organic matter out of the water inhibiting growth of dirty wrong things in the water.


Thanks for the hints and suggestions! These are some of the same things I wasn't 100% on as I built the enclosure and planed to revamp as I got better plans/ideas/resources. Like I said, by no means a finished product, but I hope with the consencus of the tarantula community and our information as a collective I can develop something that's safe and functional. Maybe some day it'll help others. That'd be rad. Keep the comments coming!