Thanks, I just wanted to make sure there wouldn't be any nasty side effects from not using a canned, 'buy it in the bottle' fertilizer.

From my reading, and the tests that I have, I'm guessing that I have an excess of phosphates (which cyanobacteria utilize easier than larger plants) and not enough Nitrogen for the larger plants to take advantage of it first.

Hopefully I can do a couple of doses, get things back into balence and let the plants keep the tank under control as they should.