flushing

Never, run nutrients to end and the cure will release and left overs. A plant will use what it needs. So by not flush you are giving her an advantage. But the cure is very important.

BTW, I would say you have 3 weeks before you would start flushing. Looks like you have about 5 weeks left total.

If you feel the need to flush, it's two weeks before harvest. Every study, however, shows that flushing is unnecessary. It doesn't do anything good, and if you start at the wrong time, you'll starve her when she's trying to build bigger buds. If you feel the need to flush, I would say do it on the last week. This way if you estimate wrong, then you can let her go an extra week without any harm done.