somebody else once posted this link, which is a good guide on algae culturing
http://www.fao.org/docrep/003/W3732E/W3732E00.HTM
the hardest part about culturing algae is to keep them from getting contaminated with other micro organisms, leading to crashes. To get around this, use good sterile practices, and split up as much as possible so you always have something left as seed stock.
That is why you would use dozens of small containers, ramping up to just a few large tanks of algae where you harvest from while restarting other new small cultures.
