Bioactive terrarium questions

Hi everyone, I’m new here! I just built my first bioactive terrarium and I’ve been noticing a few things that I’m concerned about and wanted to get some opinions.

The first is I’ve noticed white mould growing on the mopani wood and on the cork bark, I’ve tried a few things like wiping it off, increasing air flow, adding more spring tails, and not misting the wood and cork directly. But it keeps coming back. I know cinnamon is good for preventing mould in plants. So I was wondering if I could dilute it in water, and spray it on the wood and cork. And if it would be safe for my gecko and the isopods and springtails? One other thing I was wondering if it could be that I don’t have a light yet. I’m planning on getting the Arcadia jungle dawn later this week.

The second thing I noticed is I keep finding my isopods dead. They have calcium, good ventilation, and plenty of leaf litter. I ended up buying a second culture of them, and I’ve seen a few of them have died as well but not nearly as many. Also the original group died before the mould showed up, so I don’t think it’s that.

Also I’ve added pictures of the terrarium


Mould of fungi can happen. Not usually on the bark though which is strange! Was this brought from a reptile place?

Isopods wise, so you actually feed them veg etc?
I feed all ours in the viv veg and never die, just breed like mad!


Yes everything other than a few plants was bought either at one of my local reptile shops or from Josh’s frogs.

I havent fed them any vegs what type do you give them? Based off all the information I’ve seen I gathered when in a gecko tank they didn’t need anything other than the leaf litter, calcium, and the gecko waste, I also have some of my snakes shed in there because I heard that could be beneficial. But I’m totally up for giving them other foods!


Keep an eye, if persists if remove and boil or cook.

They can eat any, carrots, broccoli, mushrooms etc.
I feed them as some can be aggressive eaters and with them laying I don’t want them thinking the eggs are a snack!
Also they’ve always done better and bred better when I’ve fed. We have colonies we feed so why not feed them in the vivs! :grin:


Mold can be a pretty common thing in bioactive vivariums with wood surfaces. I’ve noticed it in mine, and it comes and goes, it’s not been problematic at all though. With a decent enough isopod population, I watched it fade away fairly quickly when I first noticed it come on, especially on cork and spiderwood, and it still does to some degree but they keep pretty busy cleaning it up.


Ok thank you! I’ll definitely try that! I make my pig a salad every morning and always take the scraps to my snails, so I’ll just drop some in for the isopods as well! Do they like lettuce or cucumbers from what you’ve seen? Also how often do you remove uneaten food?


Ok good to know! I’ve only had the tank setup for 3-4 weeks so I’m still waiting for the isopod colony to become established. But hopefully they take care of it pretty quick!

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Also does anyone know if the mould is harmful to my gecko? I’ve been trying to decide if I should move him to a temporary bin.

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I had mold on some of my wood and got rid of most of it. But in changing humidity it spread and I couldn’t safely get rid of it (without drying out my geckos). I also accidentally flooded the substrate (wood chips, not ideal for bioactives) and drowned eggs (which I only discovered in cleaning it out). I ended up just using cork bark which I still prefer along with bamboo. Green mold is harmful, white mold is harmless and possibly helpful (in small amounts). I would say if you can smell it it’s harmful.


Ok thank you for the info! The mould on the cork is minimal and white. after you mentioned the green mould I just thoroughly checked the wood and noticed on the under side where it’s close to the substrate has a little bit of it, but on the top where I first noticed it it’s white. It does still smell earthy though and my gecko usually stays close to the top.
I’m thinking if I start misting just the upper part of the tank that may help and the grow light may help too.
But removing the wood is easier said than done haha it’s foamed to the background :grimacing:

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Isopods and springtails should be able to get the lower mold. I usually pinch and remove the white mold which keeps it from spreading too far. What kind of wood did you use?


As long as it’s not there too long it shouldn’t be harmful to the Crestie.

If you have enough, the cleanup crew will clear it soon. I had this a few times (comes and goes) but the cleanup crew clear it away within a few days.

I don’t feed my cleanup crew any additional food. If you decide to put food in the enclosure, it must be safe for your crested gecko as they could Also also eat it.

What is your bio-active substrate made of and good long had it been running? They could die because of age or lack of food / water (highly unlikely for to Cresties humidity requirements). They eat CGD, I often find them chowing on it.


Ok I was thinking the same thing, I did get some chlorahexidine on a paper towel and wiped off what I could. It’s mopani wood.


Yeah they can eat that, I feed spinach etc also.
Mould is ok. We have even had mushrooms grow in the vivs.
And don’t worry about geckos eating the veg. Never seen any of ours eat it and I put in weekly!
Shouldn’t need to remove any as should eat it all, as will the spring tails!


Ok I’ve been wiping it off as I see it.

The tanks been setup for about a month. I’m using the Josh’s frogs abg mix.

It’s been mostly the large adults I’ve seen dead but I’ve seen 1 younger one.

Ok thanks so much for the info!!

I should of put this on my first reply but the enclosure looks amazing :+1:

Mold is expected, wiping it down until the enclosure is established is ideal. I’d say it takes up to 3 months before you would notice it being effective.

I get mushrooms pop up now and then, looks great when they first appear.

Gecko’s in the wild would eat fruits etc so I’m sure Cresties in enclosures would like a try also. Do be careful what you put in the enclosure.

What isopods are you using? I had some dwarf woodlice that died within a few weeks of putting in the enclosure, I thought that was it but several months later when I was having a little rearrange I found lots so they must of laid eggs before they died, this might be the case for you also… If so try not to disturb the substrate too much.

I mainly use springtails, they are amazing

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Thank you so much!!

I’m using dairy cow isopods.
I have a culture of spring tails that I put in a month ago and they just replenished enough for me to put them in again, so I’ll probably do that a few more times to make sure there’s enough.

And yes I’ll definitely be careful about the veggies!

With springtails, I just put a handful in and in a couple of months there are plenty, they breed quickly so you shouldn’t need to top them up

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Ok good to know thank you!!

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