Buy a pouch of Potassium Bicarbonate (Potassium Bicarbonate (https://www.amazon.com/dp/B07GFSM1ZT?ref=ppx_pop_mob_ap_share ) All you have to do is add 0.4 grams to 1 Gallon of distilled water.
That is the recipe for RPavlis water. It’s the perfect balance of mineralization to prevent any buildup and tastes great!
I used potassium bicarbonate (not baking soda) that I got overnight from Amazon for 10 bucks. I was going to use another product (purecrop1) but the seller pushed the delivery back twice and I couldn't wait. But it looks like great stuff.
I had read that 2 tablespoons per gallon was too hot. I used 1.5 tablespoons per gallon and it stopped it in its tracks. But most of my hairs turned brown and 3 days later some sugarleaf tips are a little burnt. But it stopped it cold in 1 treatment which was the goal.
If your early enough you could try 1 tablespoon per gallon of water. And reapply if it doesn't get it in one treatment
https://www.amazon.com/dp/B07GFSM1ZT?ref=ppx_pop_mob_ap_share
Yes, I stopped mine dead in its tracks with potassium bicarbonate I got off Amazon overnight for 10 bucks. 3 -4 days later everything is good. A few burned sugarleaf tips and most hairs on the lower half of the plant all turned brown. But it's alive and no more powdery mildew.
I used 1.5 Tablespoons to a gallon of water knowing it would be hot. You could try a couple applications of 1T per gallon and you might experience less burn if you have time. I decided to stop it in Its tracks and take the heat. YMMV https://www.amazon.com/dp/B07GFSM1ZT?ref=ppx_pop_mob_ap_share