Listen man, you got to throw out all that stuff in your head about what books say. Do yourself a huge favor and look up Uncle Ben on this site. This is constructive criticism, not trying to be a dick, OK? For a six hundred, your buds look like you picked them early, they are airy and not tight. Not to say that isn't the strain but it looks like you grew an indica which should be a relatively big yielder with tighter nugs. I vegged my plants for twenty one days, they're over three feet tall. I just chopped three of them yesterday, the one had a main cola weighing 129 grams, wet of course. I'm not saying books are bunk, I have more than a couple myself, I'm just saying what Uncle Ben says, learn to read your plants and not get caught up in the hype of growing. Use the back of your hand rule for your lights. Hold your hand under the light at the height of the tallest bud, if your hand is hot in ten seconds, it's too hot for your girls. The closer the light the better unless you start to see bleaching of your leaves. Mine are no further than ten inches from the top of my tallest bud, maybe even eight.
Here's a couple of pics from my chop yesterday.