Gemini, do feed your T's with caution :laugh: . That A. geniculata looks really overfed. I can imagine that the exoskeleton of the abdomen gets strained if it's stretched like this!

Otherwise I'd still suggest Nystatin.

Sorry for the triple post, but I need some other info as well.
What does it smell like?

Rot, stinky, humid?
Nothing, humid, sweet (coconut)?

And until we can clearly determine what it is, try and swop from crickets to some Dubia Cockroaches. They tend to munch away at the fungus.

Otherwise maybe create a temporary enclosure away from the original enclosure, with just substrate (new, different brand), a clay pot or something clay for the T to hide / live in for now and then a water dish. Nothing else, keep it small, not too humid and well ventilated. Also brush the T where ever you can before you put her into the new enclosure, the fungi might be colorless to start off with.

Then clean the tank again, fill it like you would want it, humid it up and see what happens. Maybe its something in the substrate that springs up during this time of the year, though i see you posted the same thing 2 months ago, which is unusual for winter / cold.

If the old enclosure stays fungi free, as well as the spider, introduce them again to each other.
If not, you will know which to have a look at... Enclosure changing brands, or the T.

Otherwise for now, try and get some Betadine antiseptic solution (water base). Apply this to the affected spots after brushing her, 3 times a day for 5 days. After which you should be able to notice something.

If not, alch will be your best choice, though i would not recommend it as I have no idea how it will affect the T.

Good luck, and let me know
I love experimenting with mold Fungi %_%

Marula, I definitely dont over feed. I feed once a week and not religiously either, sometimes its longer. all my ts are fat! AND its not as if i give them too many at once either! suggestions?

Beadan, firstly its got no smell whatsoever and when i attempted to brush it off it just bunched together and it looks like a scab now. also my enclosure is rather dry... let me try explain how it looks like.

U know those soft white feathers off a bird that is fluffy? thats what it looks like.

what is interesting when i was poking in there now again he tried to flick at me but his foot got stuck on it like when u try to move their legs with a tweezer and it sticks to that. it was very brief but looked rather strange.

my other t that had it, only had it on her leg, i brushed it off the first time but then it returned. after rehoming and brushing it off again it never returned and it didnt have scab effect it had now on this guy.

now to decide which stuff to try... Betadine or Nystatin??

Sticky!
This is going to sound strange, but maybe it's webbing??

There are not a lot of fungi that are really sticky, though with the right humidity, they might clump together but not "stick".

I might say that the two T's are not related in this case. Can you see if there is any wound either at the ring on her abdomen (where the said fungi is growing) or maybe underneath her, close to her lungs?

This might be something completely different... Pointing to her abdomen looking quite fat as well as the sticky substance.

Are you able to examine the substance at all? Maybe take some with your fingers and feel, smell and look at it closely? If you have, try and use a latex glove.

wouldnt say exactly sticky but it is hard... maybe its a wound from the abdomen possibly rupturing? i havent been able to touch it but via the paint brush it felt hard, thats why i described it like a scab..

I can help with mold etc, but not really with a scab... Would say I don't have enough xp...

But keep us posted, maybe create a thread call'd scab instead of Fungus?