http://boards.cannabis.com/showthread.php?t=25080

Check out that chart it will give you an idea of the cycle.

I don't have the time this even to explain in that detail but the chart may answer your questions. General Hydroponics web site - http://www.genhydro.com/
And Advanced Nutrients web sites have great information about nutrition www.Advancednutrients.com and choice your language This is the nutrient chart
http://www.advancednutrients.com/nutcalc3public/