ok u have a good set up, veg for 6 weeks or until they are 12 inches tall, blue cheese take about 65 days to flower so yes 8-9 weeks. the extent of the flowering period is always dependent on the strain. or if you dont know the starin, indica take 8 weeks sativas can take up to eleven so a mixed breed will land somewhere in the middle depending on the ratio of sativa/indica.
Good Luck!!