White Powdery Mold problem! Help!

I'm running 4 "purple paralysis" in coco coir/perlite mix. They're in a 4x4 tent under a 600w hps light with a 440 cfm inline fan with carbon filter attached. I have a ScrOG in so my oscillating fan is on the floor because it was too heavy to sit on top of the scrog. My temps range from 76-81 F and my humidity is at 20%. A few weeks ago I developed WPM on the plant in the back left-hand corner. There wasn't alot, I wiped a few leaves off with water and sprayed sm-90. Three days later I sprayed sm-90 again and it seemed to have fixed the problem, but when I looked closely a few days later there was still some mold on a few of the leaves. They were really bushy and being paranoid, I defoliated and pruned a few days ago to create more airflow through the leaves. When I was done, I sprayed thoroughly with sm-90 one more time, and I put some in the water I fed them. I really thought this was gonna be the end of my problem, but I looked today and there was three leaves on the same plant with mold on them. They just started week 2 of 12/12 and I think I see tiny little buds starting up. I'm not sure how they even got mold, my humidity has always been low, this is my first grow so everything was clean in the beginning, and I started them from seed. I'm not sure what to use now, I saw that you can only use sm-90 three times..? Now that Im in flower is is safe to use sm-90? Because they're in scrog the leaves do touch here and there but as far as I can see the wpm is only on that one plant. I don't know if I should take it out or if the other plants are already infected... Help pleasee!


This is the scrog now the picture is sideways, but the infected plant is the one by the black wires:
View attachment 2916808
This is where they're at right now:
View attachment 2916809

This is before the defoliation, you can see how bushy they are:


This is a picture of the wpm a few weeks ago, I dont have any of it now but its the same thing I guess, If anything the mh light only makes it easier to see lol

If you have more than 40days of flower left. Go get some eagle20w, and if you have 6 weeks like eagle40w. And spray your plants down with 2ml per gallon. Aftwr you've removed all infected leaves. It'll be gone. From now on. When they're seedlings, douse em in that, and every month reapply it. Until flower, then douse em once when you flip and they should be good for all of flower. I was always told nothing can cure PM and blahblahblah. But everyone always wants to go the natural way. Fuck it, it has a 20day half life, so in 40 days it's gone. But the shit is no joke. Wear gloves when you do it, and spray everything down.

Thanks for the reply. I looked into eagle 20 but found alot of reviews saying not to use in flower, but i did see a lot on an organic fungicide jms stylet oil, im probably gonna give that a try. On another note, I've already put sm90 in the water I'm gonna use for the next watering, does anyone know if it's safe to use a 4th or 5th time?

It will take a couple treatments to get rid of pm. It will keep coming back less and less and after 3-4 treatments you it will be gone.

It will take a couple treatments to get rid of pm. It will keep coming back less and less and after 3-5 treatments it will be gone. It doesn't make sense that you got pm if your humidity is only at 20%? Are you doing intake/exhaust air exchanges?

IMo I wouldnt spray eagle 20 on my plant any where in flower.

Greencure aka postassiom bicarbonate and spray, Make sure you turn your lights off so they dont burn under the HID's. Ive sprayed in late flower and couldnt taste it and no one else could either. Ive also licked the diluted solution and it had a negligible taste.

acellular said:

It will take a couple treatments to get rid of pm. It will keep coming back less and less and after 3-5 treatments it will be gone. It doesn't make sense that you got pm if your humidity is only at 20%? Are you doing intake/exhaust air exchanges?

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I think it might be gone but Im not 100% sure. I don't understand how I got it either, its even gone down to 13% but now in flower its up at 40% I just hope it stays there lol. Im exhausting with a 440cfm fan hooked up to a carbon filter. It goes from the tent, right to a window that's left cracked open, but theres a screen in the window and pantyhose around the duct to stop anything from going in. Intake is passive, I leave one of the mesh windows on the bottom of the tent open.

Eagle20 for veg only(as with all systemics). I would use Actinovate while in flower. Shit works! Spray with actinovate weekly for a few weeks. Sulfer burner would be good to. Thats what just worked for me. You shouldn't have to pluck leaves off. Spray mammas with eagle20, and you won't even have to think of PM for quite a while. If it pops up again in flower months down the road, use actinovate again, spray mammas again with eagle20.