I've got them here again! They show up every year in my balcony grow, the truth is they don't affect the plant or the yield, or anything I've noticed...
But, what are they? They almost look like dandruff.
These are thrips. You can use neem oil or insecticidal soap to get rid of them. Use blue (thrips like blue color) and yellow sticky traps to monitor your plants. If they are in full bloom the use of neem oil is not recommended as it may affect the taste of the your ganja. Also you could take them in your shower and give them a wash. Don't forget the underside of the leaves.