Sonia,
now I recall a previous post of yours saying that you'd had an unfortunate time with them...sorry I made you dredge it up 
yeah, I am sure it sucks when you get bad info - esp. from a breeder. you sort of expect it from a pet store, but not from a breeder. But thanks for sharing your sad story and the info.
I have a plexi top but I move it around on top of the screen and sometimes remove it all together for proper ventilation. I rear giant silks and they are very sensitive to humidity at different instars so it is something I tend to pay very close attention to - have to, no matter what the critter is any loss is devastating 
Thanks again,
lele
>>I only had 3 in there and I had a very bad experience with them. I had no info on them except what the person who sold them to me gave. They were two females and one male. The females were shipped to me gravid and ended up eggbound. The male died months later of a URI because they told me to keep most of the top covered in plexi or glass to keep in humidity for them and of course that was the wrong thing to do. I know the females were eggbound because I donated their bodies to my vet who had never come across R. Brevicaudata before and she wanted to do a dissection. She said they were probably too stressed to lay their eggs because they were shipped gravid and became eggbound. Probably the eggs crushed their organs.