A healthy plant will fight off PM naturally, and everything else I've seen (except some very toxic chemicals) are not cures.
In over 15 years I've literally seen PM on only one of my cannabis plants. It was in veg in a slow air pocket with too much humidity for the temperature. Keep your temps and humidity low (68F/20-25RH), your airflow high and avoid dense canopies which slow air movement.
yeah my apartment sucks. Maybe i need to get some better fans
I've had the fortune (till recently) of growing in very dry environments. My standard set up was a 4x4 flowering area or a 4x4 tent, set up within a bedroom. An a/c in the window provides cooling (with the water catch tray cut out to prevent icing up in the winter) and your airflow is set up through fans.
Using high micron filtration (like 3M furnace filters) will remove most of the spores of PM from your grow environment. :)