switching to flower have few questions

ebb and flow system been vegging 4 wks look great sry no pics question is they r currently feeding 4 times a day in veg light on 20/4 buckets flood 15 minutes and then drain i ve been told not to feed in dark so when i flower how many times in twelve hrs should i feed?
and i could make feedings last 30 mintues or longer should i lengthen time buckets are filled before draining back to res? thanks for help in advance

I flood 3x's in 30 min intervals in veg and flowering stage when lights on only.

should have mentioned i have 12 2 gal buckets ..........what do you have?

3x3 grow tray