I do not follow a strict schedule. I do just follow my TDS meter mostly. I change the filters out about every 6 months to a year and the RO about every 2-3 years. One thing that I would like to note about the video, it is quite informative, however many people may not know what the abbreviations are. Example, there was a lot of use of TDS but I did not hear a reference to its meaning. I know it, you know it and most of us know it, but I am sure there are a lot of noobies that do not.