You know after reading that thread, I read my Miracle-Gro bottle and it lists 0.10% Chelated Iron. I read somewhere that Celated Iron was good for something in an aquarium, I just don't remember what, or where I read it. I think it had something to do with battling hair algae, but I'm not sure. Is 0.10% a lot?
That thread has me thinking of changing, I just really like being able to go to the store and but Miracle-Gro, as opposed to having to order online.
I have had really good results with it in the few weeks since I started my culture. I first got the idea of using MG from Melev's web site:
http://www.melevsreef.com/phytoplankton.html
And he was using tap water.