| well there is the species Isochrysis galbana as you noted.
this comes in two strains, T.Iso and i think C.Iso, the T means its from Tahiti, but i dont recall where the C.Iso was isolated at.
then there was Nanochloropsus, this is the most common type that is used to create green water.
at the risk of providing incorrect info, i will defer further info to Erik
__________________ Show people you appreciate there advice, click the  icon under there name and give them Reputation points | 
