Thanks for the replies guys, especially to you Stanley! Your post was incredibly helpful.

The tanks are made from small glass sheets that are held together with what I believe to be marine silicone rubber. A seperate sheet of glass makes up the lid and this has a very small circular vent placed in it. I took the T's out as soon as I realised something was offish a few days ago and put them into clean deli cups (Yes, separately). I also thought it might be the coco husk so I cleaned the cages thoroughly and microwaved the coco husk for around 60 seconds - even before microwaving the substrate I could see it wasn't the source of the odour. The smell is confirmed to be coming from the cages. Since moving the T's the B. boehmei has recovered quite well but the C. fasciatum has got decidedly worse - it is now not eating and remains bunched up (I suspect stress is also playing a factor so am trying to leave it alone). I have a feeling that it has been so much more severely affected due to the fact that the Tiger rump is a fair bit smaller than the Fire leg.

After cleaning I found the smell was much stronger than usual. I know the vinegary smell you are talking about Stanley but this is not exactly that smell. I bought the cages from a pet shop quite a while back - possibly 3-4 months ago so surely the silicone has cured by now. I have a good feeling it is just that the manufacturer of these attractive looking cages was trying to cut costs and this was the first place he could - by buying cheap silicone, sadly my T's will pay the price. I won't buy these cages again and I'd advise anyone who is looking at them to rethink their choice.

I'll be looking into simpler permanent housing from now on, possibly just high quality tupperwares of various sizes to accomodate terrestrial and arboreal spiders.

Thank you all for the help, will keep you posted.

BP

electro78 wrote:

That was a mouth full. But very informative. I didnt realize this about Coconut Husk. How often should substrate be replaced?

Our standard rule of thumb is that "generic" substrate (i.e., not based on some weird properties of the substrate itself, but rather on the use of it by the enthusiast and the tarantula) should be changed at least once a year, usually just before the molting season. But, it should be changed more frequently if it begins to smell. An odor, especially a foul one, announces that too much dirt or other organic matter has accumulated. Other enthusiasts use different guidelines, however, with a few almost never changing the substrate.

Bushpilot wrote:

... but the C. fasciatum has got decidedly worse - it is now not eating and remains bunched up ...

Get this one into an ICU as soon as possible. Doing so won't do any harm and it very likely will help.

Hope this helps. Best of luck.

Here's an off the wall idea.
Mark the two glass cubes that the T's showed signs of DKS.
Get two curlies I hear someone on this site is giving some away for free on this forum.
Place them in the container after you have washed them out and use different substrate. Let's see if we have the same results.
Or give those containers to someone who is willing to experiment. Maybe someone who has their own feeder supply.

Let's try get to the bottom of this. Maybes send a scraping of the adhesive glue for analysis.

This is great info thanx guys gonna move my ts now!!!

Bushpilot, try and make your own tanks, with bostick`s marine silicon... that`s what we do... will build a new cages in the week to come..

We will take some photos and explain exactly what we did and used. Keep your eyes open for the tread