Powdery Mildew - need advice

I'm a new grower and this is my first exposure to PM (see pic)
Background: Moved flowering plant from closet to garage (4x4 grow tent). Temp diffs (night = low 50s -> day = high 70s) and increased RH (as high as 60%) I think caused PM to take hold.

I have:
1. Added a heater to keep temps more in range (65 - 75)
2. Changed light cycle to run lights at night (9pm - 9am)
3. Began treating with Potassium Bicarbonate (2x a day in solution, sprayed on base and stem, branches, etc). So far can't see a real change.
4. Ordered a small dehumidifier.

Plant is maybe 2 - 4 weeks from harvest. Rest of plant looks fine - no PM spots on leaves or buds - just at base near soil and on up stem about 4-6"

Pistills are starting to change color a bit and there are ALOT of Trichomes on leaves and buds - so I could harvest, though yield will be reduced. I tend to prefer earlier harvests (clear/white TCs, rather than late amber. And we don't smoke, we eat it, so color, flavor are not goals).

I am watching day to day.
I'ld like to let them flower longer for more yield, w/o sacrificing the whole deal.


Suggestions, Comments?

Thanks

Originally Posted by ihatebud

If you harvest the buds and they have PM, look into water curing them.

How would I know if the buds have PM? - short of seeing the white mold on them - which right now I don't.