2004 chevy cavalier coolant issue?

My cavalier is loosing coolant and we cant seem to find out where. We've used the UV dye, and have no been able to find anything. The reservoir has to be filled about every 4-5 days. It started out as a fill every month (about 10 months ago) and now progressed into every few days.

The temp gauge stays at 195 while driving and while idling.
The oil does not look milky .
Its almost at 195,000 miles.

Can a faulty radiator fan, cause the car to use coolant fast? Not sure if it is kicking in but going to check it out.
Thanks