I wouldn't mess with the light cycle at all for a couple reasons; light stress can induce herms, and I've got a perpetual crop, so I can't just do it to the finishing ones, and if there WERE herms, they'd pollute the rest of the girls.

Letting them get dry and droughty is better and easier IMHO.

Molasses mix- I just dump a glop in my 2.5 gallon watering can and call it good. A 'glop' is like a tablespoon or so