I have a colony of lasius niger and grows very well, and they are still living in the tube...do you know how many workers can live in???and when is the time to move them in the farm???
Ants like confined spaces, a test tube, assuming 150mmx15mm and a 3cm water reservior, will easily accomodate a colony of 100 Lasius niger.
Lasius niger are notriously hard to persuade to move, best bet is to wait for the water to have nearly dried up, then setup the farm, and leave the test tube in a basin attached to the farm, once the water has dried up they should start thinking about moving, but it can take weeks or months!
Yep about a 100 would be not a problem for this species. ;) At least if the water don't dry up. (Like Mizst said ;) )