you need a 30x microscope to see if the thc is ready or not, is the only way you start to flush. on my big bud hydro grow , i didnt have a microscope and just went off the facts on the big bud and started to flush on the latest day of flowering ( 56-62 days of flowering) i went with 62. and that bitch came out excellent. but try and get a 30x micro if you can. just water only 7 days before day 62.