Konuray, your pictures did not come through and they are necessary for any chance of a diagnosis. As it stands, I would suspect a simple fungal growth of mycelia and hyphae, not at all uncommon in closed terrariums.

But no way of telling without pictures.

Uploading pics. Thanks for the answer

You can’t post pictures (easily) in an opening post, but you can post them in a subsequent post.

post pix in a reply.. same box im typing in ..

if i understand correctly.. you just set up these 2 terrariums... was EVERYTHING you put in them sterile .. media.. rocks.. stones.. etc ... and the tanks themselves ... watering cans ...etc.. etc ...

of course you can not sterilize live plants ... but they can be bare rooted.. and gently cleaned ...

but if everything else was not sterilized.. you can generate all kinds of molds.. mildews.. etc ... until the system stabilizes itself ...

the link shows tells how to sterilize media ...

ken

https://tipnut.com/sterilize-soil/

ps: who knew there was a home disaster forum.. lol .. im going to go check it out ...

Thanks, i am gonna check out the link if i am doing anything wrong ✌🏼

Cheers

Thank you so much all of you!!

if the few pennys it costs to bleach everything out.. and sterilize the media.. WHY NOT DO IT ...

i just remember.. back int he day when i was germinating thousands of hosta seeds.. one minor problem in a tray would wipe out the whole trayl. and after spending the extra time sterilizing.. i never lost a tray again ...

frankly.. the white stuff looks like cotton ball or cottonwood fluff.. or the fuzzy sweater you were wearing when you reached in there .... but to be sure.. the pix are very hard to look at.. being straight down into a glass vessel ... something about it makes my head go all mc esher ..lol..

https://duckduckgo.com/?q=mc+escher+artwork&t=ffcm&iax=images&ia=images

short of pulling everything out.. i might try a spray of diluted bleach on the stick.. of try painting some one with a small brush.. just to stop the process ...

if you had baked the stick before use.. then this wouldnt have happened ... oh well.. live and learn ... if you are an optimist.. you would say.. this is all a process of ma nature. i i built this things to watch it.. so let it run its course...

if you are a pessimist. i suppose you would say.. this is an epic fail.. because something happened i didnt predict.. so i must destroy it all ...

the lazy person.. me.. would declare it a success as a process of nature.. and not bother pulling it apart. .. lol ...

ken

I was walking the dog this (early) morning and noticed on the wet leaves, the same "shmarm" (my daughter's word for gunky stuff), and thought of your post. Wet ,fallen leaves, too much moisture, no sun and a temp higher than usual for this time of the year caused it.

No help, but I was thinking about your dilemma.