How are you getting rid of the PM in the rest of the house?
a lactic acid (milk / water) or citric acid (lemon juice / water) misting spray will do it. misting then wiping down plants with larger leaves is even better.
On the plants I'm also using citric acid or neem for non-flowering ones. I think mine comes from my garden where there was a lot of dead undergrowth I cleaned out last weekend.
for pm ? neem might be a bit harsh for pm but it will work.
Also, PM doesn't die in freezing weather:
"For the fungus, temperatures below 43 degrees Fahrenheit
we officially have no pm here then. we're at -55c or -67f with the current windchill. my car hasn't run in 3 days.
and above 93 degrees can delay powdery mildew development, and more extreme conditions can even kill the fungus."
oh for the dream
... 
Felonious' cousin-in-law works for one of Canada's licensed producers and he says that the only way to get rid of PM permanently is to ditch the dirt and grow hydroponically.
it helps but you can still get it. most times it comes from other plants. it's easy to bring it in from outdoor and indoor house plants will harbor it even in winter.
it won't get into the media and repeat cycle after cycle in most hydro, but you still need to look at other sources. good air circulation really helps.
I was planning on growing hydroponically when we move to an apartment but that's not for at least 6 more years.
passive or active hydro ?
My perception of hydroponics is that it's a lot of hands-on attention.
passive hydro can be easy but can tie you to the grow. active hydro can be a steeper learning curve at first and requires more gear / investment.
I have hard enough of a time keeping up with them now so I'm not convinced I want to go to a hydroponic grow but I also don't love the fact that PM is not only killing my plants but reducing their potency so that's definitely something I don't want.
if you like the way you grow now then look to environment control first to eliminate it.
Not having done it I'd say the easiest hydro is hempy. Perlite in a bucket with a hole about an inch from the bottom. Same nutes as you're using now except ideally you check the pH.
@bluter and
@PGA Caddie grow that way.
actually the hole is ideally 2 1/4 to 2 1/2 inches from the bottom of the bucket.
hempy or sips is probably the easiest to run. both are passive hydro.
hempy is by far the cheapest method and requires no special purchases or equipment. dollar store growing. it also releases you from soil type media or coco which can be problematic in apt / condo type living spaces.
Does your CIL count coco as hydro? It is technically though it might not offer the same anti-PM qualities.
curious about the same. it holds on in peat base media if you re-use.
I'm confused. How will a grow style or system prevent WPM?
it can harbor in soil and peat type media. other molds do as well, even beneficial.
