Flood and drain time

Is 6 minutes enough time every 3 hour cycle in a 24 hour period, for a flood and drain table with nutes 3 inches deep on 6" rockwool cubes?

Thanks

I use 6x6 Rockwool blocks and I am at week 3 of vegging . I water my girls once a day when the lights come on. When I switch to 12/12 I will water twice a day. The big blocks hold a lot of water.

My pump runs for 15 min. 6x a day . I use hydroton clay ... not to sure about the rockwool...but this is the feeding/watering schedual I've always used and it works good for me. Good luck