Late to the thread, but just wanted to add for general info sake that I run really simple... tap water left sitting for 48 hrs, then it's PH adjusted, and then I follow the Lucas formula using just FloraNova Bloom.
I get very good results.
When the FloraNova Bloom runs out I'm going to switch to the MaxiBloom from General Hydroponics Lucas method. I've heard great things.... much cheaper, and if stored well, an indefinite shelf life. With my small annual grows, I've never run through a pint of Bloom before the expiration hit.
You really can do this any number of ways and be very successful. I've done some 3 part nute grows before and frankly it's a lot of fun! Especially if you have any tendencies to be obsessive about new projects. But, don't fret... pick a method that matches your personality... you can choose a laid back method, a full blown OCD method, or many different levels in-between... and if you follow it closely, you'll be rewarded!