Guys do well day and night. If you don't have much experience on erie I would stick to the day till you do. Depth depends on where they are. Learn to use your depth finder. Which means get it off the auto gain setting and get out there and start trying to catch what you mark, you will learn in a hurry what it is showing you. Bait shops will tell you generally how deep they are getting them.
That's my 20 years of erie eye fishing in a paragraph.
Better too far back, than too far forward.