4x8 flood and drain rockwool

so im almost set up with my grow but i have a few questions, i got a 4x8 table flood and drain, gunna do rockwool cubes, the main question is about flooding.

What inches would I really need to reach on my 4x4 cubes to make it sufficent, since rockwool holds water so well i was thinking only needed to run it about 3 times a day when the light is on and about a inch up on the rockwool.

How many liters will i need for the table?
How high should i flood on the rockwool?

I need a few suggestions or ideas

Are you going to have anything around the rock wool?

I use hydroton around my rock wool in a similar system.

If you just plan to use rock wool alone you will get no roots leaving your cube.

I think you could support a 1'6" plant to maturity with a 4x4 cube

I go from 1" to 6" cubes, and I have Hydroton up to the top of the cube.

I feed by hand, just plug in my pump.

I flood and drain 3x each feeding time 4 - 5 times per day.

so far my plant in Flower is happy!

I have a veg with plants over 130 days old with the same system, ebb n Flow.

I will be covering the whole table with a mylar type sheet. No light will hit the table at all, if the 4'' cube cant support how big they get ill be putting some mesh up top for them to lean on.

Roots dont grow into the lights i got that figured out.

"I flood and drain 3x each feeding time 4 - 5 times per day."
I dont correctly understand that statement.

thank you though

I need to bump this up