no..once the root system is established youre supposed to keep the water level half an inch to an inch below the bottom of your net pot. keeping the rockwool moist at all times promotes stem rot which you most definitely do not want
When I have roots established I move the rockwool cubes into net-pots with Hydroton - then into the tubs.
I keep the rockwool well above the water level, and let the root system grow down thru the Hydroton into the water.
Once I have established roots the rockwool never gets wet.
