CrappyPappy, I have no idea on the answer to that question. Last night was my first time to try night fishing specifically for crappie and first time with a light. I was fishing about 12"fow so I sunk the light half way between surface and bottom. I will say that most of the crappie I have caught from this lake have been in the 16-20" depth range. It is a deep clear Lake that holds many great game fish, but confounds me when trying to find crappie every trip. I keep going back because of the two lakes that are close I like it better.