Cool. Well my setup is exactly like yours now with the exception that I am only going to be making phytoplankton. Now my last few questions. I went to a couple of the sites you suggested to obtain the cultures and I'm confused on which to buy. I am really using this for 2 small clams in my 120gal tank. Should I get the Isochrysis G. or ocean green. From reading their captions I don't see much difference in these cultures from Dt's which I currently use except for they are not concentrated like Dt's. What is your take on this? Lastly, after the culture has been "simmering for 7-10 days how can I be sure that it is going to be helpful and not harmful to my tank; meaning that I did not harvest the culture too late. Thanks.