Don't worry, they look fine. The leaves will yellow and drop towards the end of flowering because the plant is dying, cannabis is an annual plant meaning it completes its life cycle within one year.
What strain is the plant that's 7 weeks into flowering? And when you say 7 weeks do you mean that you switched the lights to 12/12 7 weeks ago, or do you mean you first noticed flowers 7 weeks ago? If it's an indica dominant strain then it should be ready to harvest after 8 to 9 weeks of flowering. If it's sativa dominant it will take a couple more weeks.
GTC21 Reviewed by GTC21 on . problems + harvest ok heres some pics of my plant its about 7 weeks flower ph 6.5 using cana A_B in soil (1) is she ready to harvest (2)why is it losing its leafs like this (3)ive been having a lot of trouble with yello leafs not really burnt o sorry about cam pics not very good Rating: 5