Marcum v385

Every review I read everyone seems to love this unit.. I bought it about two weeks ago got to use it on deepcreek and I was so disappointed I didn't use it the next day at all.
 
Screen was blurry and I couldn't see a thing until I hit the bottom of the lake. it was about 20fow .. but my brother has the older model the Marcum v380 and he could see clear as day.. We messed with all of the settings for hours but couldn't find a solution. just seeing if anyone else has this unit and some options I could look into. thanks, ed