How often to replace will very on water quality and type of anode rod used. General recommendation is 3 to 5 years. with magnesium rods being around 3 years and aluminum around 5 years. I don't ever drain mine all the way, I just do this at least once a year: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-wTghx8gR4XE.html
You don't ever flush out your water heater? I do mine every 1 to 2 years and I do get sediment out that can build up in the bottom of the tank. Otherwise, thanks for the video and yes, replace the aluminum rod about every 5 years.
