Exactly! I try to do everything right and still I got corrosion. Im going mad trying to work out what it could be.
How about your room temp.? Maybe you are living on a cold place that is why it still getting corrosion.
The ideal temp is around 60 and 75 degrees Fahrenheit if you get lower than 60 some components will always fail.
Im in London, UK. Outside temp is like 8c during the day and 1-2c on some nights. Inside temp is only 3~5c higher.