i'm a great advocate of diy for reef aquariums, but...
I don't see the wisdom of a one-mixture-fits-all concoction. Any chemical additive that could have an almost immediate and profound effect on your corals should be separate, so that it may be independently measured and controlled. The axiom that says, "if you can't measure it, don't add it" should apply here. Who has test kits for heavy metals like chromium, nickel and zinc?
I think it's a bad idea to throw chemicals into the water without measuring the initial levels, having an acceptable target range as a goal, knowing why it's being added, and understanding the long-term effects and risks. The recommended method of dosing and observation is more of a seat-of-the-pants apprach. As the balling method's instructions (
www.reefdreams.de) state, "the requirement of each tank is different, it has to be detected in the course of some days on your own," (i.e., through observation and tinkering with the dosage).
Where's the science behind the method? How would you know when you've reached exactly the right dosage? What are the indications of dosing too much?