I'd suggest you focus A LOT MORE on measuring testing etc light and CO2, learning that and generally about how and what good plant growth looks like, ,nutrient dosing is the easiest part of this.
Once a good lower range light is set, then nutrients, all you have left is the CO2.
Measuring CO2 is the trickiest of all, but lower light, good dosing + sediment rich (eg ADA AS or DIY worm castings, soil etc) etc makes this simple.
See here for a good article on light and CO2:
http://www.tropica.com/article.asp?type=aquaristic&id=142
I think folks seem to think dosing methods and nutrients are far more important or critical etc than they really are, then they get over focused there, lose sight of the larger picture.
PMDD basically was for low, very low light systems.
I used more light, so I reasoned I'd need more nutrients and more CO2 than PMDD. I had high PO4 in the tap and was growing more plants and doing much better than those using PMDD.
I also had no algae.
EI is 90% PMDD, I just made a few changes, the math is also contained in PMDD for serial dilutions, the same that are used to show the build up of nutrients using water changes and dosing. Many old timers had been doing large water changes + dosing thereafter to keep things from building up too high and also not running out.
This is not my concept, just a rational I supported.
I also know Paul and Kevin personally.
Regards,
Tom Barr