That is the whole thing with hydroponics being easy and hard. Its simple as fuck once you have the PPM/PH meter, if you are reading the tools you are not going to have problems. Now guys who have grown for years will say you can tell by the plant whats going on, you don't need a meter. They can because after years they know what is what. Most people on this forum are trying to figure out what is what, and is going to kill the plants because people say you can do it, just read the plant. DUDE!!!! Its their first hydro grow, don't be stupid. I myself tried soil and can never do it, with hydro I check them once in the morning before work, when I get home, and right before lights out. On EBay they have cheap as hell meters, and they are better then non, do what makes you feel good, not what people think you should know.