I have a corsair h60 water cooling unit, and it has been in use for little over a year now, still running well. But I have been wondering will this unit require maintenance? I believe it is a closed unit but I hear water cooling units should have their water replaced frequently, is this even possible on the unit I have? Should I be doing anything to keep it running well at cool temperatures? My cpu cores tend to run at 35 to 40 degrees Celsius but I have never recorded these temperatures during high intensity tasks such as stress tests or gaming. Also should I expect to have to replace this unit within the next couple of years? I have not had any problems with cpu heat or cooling I just want to make sure my pc stays like that. Many thanks, Tom.