Help!! I think I'm breeding PM in my ventilation system :/

[MrShpongle]

The one time I got PM was in the exact same situation as you. Normally I run indoor air through my hoods and exhaust outside, but one winter I decided to reverse it: 30 degree outdoor air cools better than 65 degree indoor air, and the warm exhaust air could help heat the house. Kill two birds with one stone, right? Well, I ended up with PM... bad. I lost 1/2 my crop, got reduced yield from the other 1/2, and couldn't put anything into the flower room for a month until the last infected plant left and I could sterilize the room. Never gonna make the mistake again.

Someone else mentioned it, but a key thing to watch out for is significant temperature swings. PM spores don't seem to germinate if you can keep your temps in a narrow band (10 degrees or less). For me, that means using a heater in the flower room during lights out to keep it from dipping below 67 (lights on temps max out at 77).

P.S. The one time I got PM my RH stayed under 30% the whole time, so don't assume that low humidity will insulate you from it.

 

[Team Microbe]

The one time I got PM was in the exact same situation as you. Normally I run indoor air through my hoods and exhaust outside, but one winter I decided to reverse it: 30 degree outdoor air cools better than 65 degree indoor air, and the warm exhaust air could help heat the house. Kill two birds with one stone, right? Well, I ended up with PM... bad. I lost 1/2 my crop, got reduced yield from the other 1/2, and couldn't put anything into the flower room for a month until the last infected plant left and I could sterilize the room. Never gonna make the mistake again.

Someone else mentioned it, but a key thing to watch out for is significant temperature swings. PM spores don't seem to germinate if you can keep your temps in a narrow band (10 degrees or less). For me, that means using a heater in the flower room during lights out to keep it from dipping below 67 (lights on temps max out at 77).

P.S. The one time I got PM my RH stayed under 30% the whole time, so don't assume that low humidity will insulate you from it.

Really?! You made me feel a lot better about my situation now...

I closed that vent off and ran a shorter intake connected to a hepa filter to send cold air into my room. Now I just re-circulate my close-loop system for my hoods back into my "lung" room in which my 2 tents are in. Temps stay in the 70's and lower 80's now and I am so happy!!!!!

I've been taking preventative measures as well, because I sterilized the tents but I know I didn't get every spore. I talk to a grower out in norcal and he's generous enough to spit endless organic knowledge at me whenever I ask questions. Taught me a lot about insect frass and its benefits, as well as foliar feeding with compost tea to get those micro organisms to cover your leaf surfaces; protecting against PM. Since I cleaned my room I haven't seen it, but I'm still staying on top of things because it's only been a few weeks or so. Glad you got over it man, it's really discouraging isnt it? I felt like I was doomed...

 

[Team Microbe]

Also, I added insulating ducting for my intake because when I took my old non-insulated ducting out I DID find a moist film on the walls of it.... PM CITY!

The warm room caused it to sweat once the cold moist air from the snow/rain entered I think. Just wanted to add that incase it helps you in the future at all

 

[trichrider]

there is glass in hood?

I agree with the temp differential creating favorable conditions for mold/mildew...especially when it's outside air.

sulpher burner at intake is my suggestion (to rid duct) or eliminate outside exposure.

good luck.

 

[Team Microbe]

there is glass in hood?

I agree with the temp differential creating favorable conditions for mold/mildew...especially when it's outside air.

sulpher burner at intake is my suggestion (to rid duct) or eliminate outside exposure.

good luck.

yep hoods are air cooled with glass but I already took that ducting out and tossed it, installed insulated-ducting (the key to my problem) and installed a HEPA inline filter just to be safe this time. I cleaned the room the best I could but I think the real savior was insect frass/compost tea foliar spray (bacteria-dominant)/neem oil in rotation every few days. It solved my problems naturally I feel like. This was a big wake-up call to stay on that preventative train and not slack anymore... I'll never let this happen again!!

I've been PM free for 3 weeks and counting... thanks for the wishes brother!