Help- Need Hydroponics 101

There are probably many people like me out there- I've lurked all over this site and watched a LOT of the related YouTube content about tower builds.  

I’ve built a tower for myself and my father in law has just completed one as well.  Now after about 5 weeks of growing, I realize that I don’t know what I’m doing….

I’m using the general hydroponics nutrient and following (or trying to) the grow chart. http://gh.growgh.com/docs/Feedcharts/GH_Maxi-REC_03216am.pdf

Every week, I add nutrient per the chart (following Maxigro row)  I did adjust my PH down to about 6.

I didn’t realize that I need to monitor water level and of course- that has screwed the system up.  So I added water and nutrient last night

Is there a good basic How to instruction to run a tower???