Jesus christ...If you're gonna go cheap on hydro, buy a 6 dollar water drop pH test kit, pick ONE nutrient line, feed at 50% recommended strength, and slowly increase the strength over the course of a few weeks ONLY if the plants look like they need it. It's really not rocket science, thats how I did DWC for like a year with good results before buying a TDS meter and a pH pen. Even then, I only bought those because I had disposable income at the time, as a result of several sucessful hydro harvests...lol