PH and Nute-lock

Hello, i've never really looked at pH and nute-lock so i have a few questions.

My pH is 7! I no it should be around 6.2 - 6.5 a think, any ideas on lowering it?

What does nute lock look like? And how is it caused? How do you know when you have got nute-lock?

This is a ph table, detailing what ph is needed for absorbsion of the various chemicals. If lockout occurs, the symptoms can vary widely depending on what nutrient is being locked out. If calcium is locked out for example, "rust spots" appear, if nitrogen, yellowing appears. Rather than go through every concieveable posibility, go buy a ph meter, learn how to calibrate & use and use it every time you add anything to the substrate, ensuring the ph is within your preferred range. Also, buy a good book on growing, Marijuana Growing by Jorge Cervantes is highly recommended, so is The Marijuana Grower's Handbook by Ed Rosenthall. I do not mean to sound patronising when I say this but the best single investment any new grower can make is not a high powered light or fan or super nutrient, it is a grow book and the time to read it. Green mojo dude, welcome to the wonderful world of growing. W