Coco Mat and Nutrient Schedule

I'm using 4" rockwool blocks on top of a 1/4" coco mat on an ebb & flow table. Everything is just ducky so far and the bulk of my root mass for each plant now exists in the dark moist area beneath the coco mat.

My questions are

1. How often should I cycle the nutrients to wet the root now that they are out of the RW and exposed to more air?

2. Should I reduce the number of nutrient cycles during the dark hours to avoid root rot?

Any other constructive thoughts are also appreciated.

Thanks