Settings are really a personal preference, and different from person to person. I suggest you buy the DVD Ben Parker Breaking Bass. He went into great detail about getting your Lowrance units tuned to a general setting. I set mine to his general settings then fine tuned my units and now they're flawless. That's the best suggestion I have for you.
"If people concentrated on the really important things in life, there'd be a shortage of fishing poles." - Doug Larson