You can totally do the six filters once a year, that's how I usually do it, but the smoke is destroying filters pretty quickly. If you want minimal brain power,

You can totally do the six filters once a year, that's how I usually do it, but the smoke is destroying filters pretty quickly. If you want minimal brain power, getting them every 3-months (or what your normal cycle is) is fairly optimal, since getting new filter === time to change the filter.