IMHO you will want to wait a bit. There are loads of white still and the buds will fatten as they mature. A microscope is a great tool to have and can be bought for only $12.99 at RADIO SHACK. When to harvest is a debate about percent of amber trichomes. Some prefer lower percent of amber for a headier feel, more amber for that heavy stoned effect. Read up on percentages of amber trichs and get a microscope. It is the best $12.99 you will spend on your grow