first time hydro grow op

[Turnagain Arm]

i'm starting a deep water culture system 4 plants 10 gal but when i put the rooted cuttings in what should the water lvl be at?

 

[Akornpatch]

Close to the bottom of the net pots so the bubbles splash water on the roots.

 

[Turnagain Arm]

thanks for the tip