Light magenta nozzles missing

I have normally 3-5 nozzles out in my epson s80600 light magenta. Lately when I come to shop next day half the nozzles are missing out of it. Have to run medium to power cleans to get back. Had to do a head wash one time to get it back. Still always have those 3-5 out though. Any ideas?
One thing weird is my light cyan is perfect and my light magenta is not. They are on the same head and captop. Which probably rules out that is not bad captop. Any other ideas? Put new ink cartridge in as well. Not sure if these printers can get air in the lines or not?