Yeah, cyanobacteria are a pain. We just classify them under the phytoplankton generally and let the scientists who actually specialise in the ocean primary production species sort it out. (Which they haven't managed to yet)
Still, a very nice terraforming write up. I'm not sure over your usage of algae, I think phytoplankton (as a blanket term) would have been more appropriate, but that really is quibbling - it just makes a little more sense (to me) given the degree of the earth's primary production that the Planktonic species perform, and what that would mean in terraforming mileage as well.
But yes, I would suggest plankton as an additional term if you're going the aquatic route, since the more complex algaes would take a while to form in the steads of their smaller, drifting cousins. (Especially as most algae utilise the planktonic system to reproduce and spread their sporophytes/offspring)