I just realized a better response: flower when the roots are ready.
That means when the roots have grown to the point that the container becomes dry in a couple days. Nothing worse than watering 1 time per week in flower.. I like the plants to want water nearly every day to get the best results, for me.
I don't like having to water 2x a day but during week 5&6 it's not uncommon and provided you are around to do it and they are dry you'll be able to get really good results.
Nothing worse than soggy roots and the problems that go with it. (Bugs, rot, low yield)