Water level???

hey everyone i am fixing to embark on my first DWC grow. my main concern is water level what does everyone usually have theres set at? The guy at the hydro store said if you have it too high it can cause algea growth on top of you medium so i am thinking about having my level 1 or 2 in. under my netty pot! any input on this or input on what you guys have yours set at i would greatly appreciate it!

thats about right just so when the bubbles break it will mist the bottom of your pots.

Check the link below (didn't you raise this question awhile back?)