@diedrichg after setting again group permissions, it now seems to work.
But everytime when i save, go out of pools tab and get back again in pools/acl than he changed from advanced to basic and maybe some other things...
But actually it works fine...
What do I have now for possibilities to limit the space of some directories... So maybe the shared should not be bigger than 20GB or something like this... Is it possible to do this by settings or do i have to create different pools fot this? (Pools i don't like that much, because i can't change it when i want to change it later on)