Best Time Of Day to Water? Hydro - Ebb and Flow

Im about to flower and am flooding trays twice a day. I plan on continuing watering twice a day.

Question: Considering lights come on at 7pm (for 12 hours), what times should I water/feed?

The hydro guy at the Hydroponic store said not to water during dark cycle. He recommended water at 9pm and again at 1pm. Feedings sound awfully close together to me. Is this normal feed 4 hours apart? Or would it make more sense to feed at 9pm (2 hours after lights on) and again at 5am (2 hours before lights off)? Thanks for the advice!

bump bump.

For future reference for those who have the same question. I learned to water 2 hours after lights on and once more 4 hours later. Per advice of my hydro guy and works great for me.

lol, awesome.

you should water after turning lights by 3hrs 34mins 12seconds. if you dont then plants will die! lol jokin, its not that important, you can flood more times than twice, i do 6x