Did you buy the device? If your home is indeed "dust free" you wouldn't need this filter (and cleaning it won't clear the small things you probably want to filter, water also damages the filter). If you're using HEPA you can't tell their life just from the way they look.
If you could do that all and still chose to buy the device with drm, locked hours and a proprietary fan with filter there is flawed logic way before you bought the device. Even going forward a box fan and filter is cheaper and better.
