I use my coppers all season. I have different lenght coppers for different depths. I run a 100,200, 250, 300, 350, 400, and a 500. The 300 and 400 have been my most productive over the past 2 seasons. When the thermalcline sets up better, it is a little easier to figure out what coppers to put out. Don't be afraid to run coppers out of temp. both warm and cold.