Proper water level for DWC?

[livepure]

Hi guys, I'm finding a lot of conflicting information as to what the proper water level for deep water culture is. Right now, it seems that the "best way" is to submerge the net pots of the resevoirs to the necessary level (.5-1") and once roots are showing through, lower the water level to x amount of inches below the net pot.

extra bs:
Early on in my grow, I almost killed my plants by not submerging the net pots at all. With some help from a member and some experimentation, I was able to revive them, and now have the water level sitting at about an inch above the base of the net pot. This seems to be working well but I would still like to know if it is optimal.

 

[rhetorrikz]

I just hand watered once a day untill some roots hit the res then lowered the water level a couple inches..
add good air stones

 

[Cultivator]

dont sit net pots in the res. keep a clear gap and just top feed until roots pop through net pots and then stop top feeding. Roots should show real quick when top feeding, couple days or so.