Hey Guys. Here is my system. I know the bottom filter needs changing when all the blue is gone. The next one up, white one, was changed about a year ago, which made the fillup half the time to what it was before it was changed. The reason I ask, is I am now getting spotting on the windows, even thou my water is normally 0.00 or sometimes 0.01 max 0.02....Its also taking forever to fill, about 8 hours. Any advice muchly appreciated.