One week before the last week you give something like Flawless Finish, for the last week only plenty water. For the last week only pure water no bambé or mollases or any other additive.
At the last day of the last week that is the last time you water before darkness, you give water as usual and you drop ice on the top of the soil, immidiatelly you put them to dark and let the ice to melt slowly, let it 3-5 days in darknes, if you see that water is needed you can add with no problem, is better to harvest when the soil is a bit wet. Thats it!👌