Every Time i grow indoors, Powdery Mildew!!!

intche

Member
Why is it that everytime i grow, i have to deal with PM. its very discouraging. Ive used so many tricks. It just seems to come back even stronger!

Ive used baking soda n water, sprays from OSH, neem oil, sprays having a mix of neem and fungicide, increasing airflow, temp moderation, removing free standing water (instead of flood switched to sprinkler) sealed room off.

I want to start another grow because i just cant bring myself to selling all my equipment. But i am afraid of PM!!!!

what do you guys think i should do? pull everything out and do a massive rug doctor clean and bleach walls!?


ALSO

check out www.intche.org
 

intche

Member
humidity is ranging from 40-60%, and in past it has been hydroton with flood. then i switched to soil with sprinkler system.
 

intche

Member
whats a good way to lower my humidity other than getting a dehumidifier?
i used hyrdoton in the past with a flood setup. then i switched to soil with a sprinkler system.
 

fruitrollup

New Member
sprinkler? sounds wet... does this pm happen after cure? before harvest? when i got it once it was because i put humidifier disks in curing jars. i dried it to much tried to re wet and keep= got pm. either way its probably a dampness issue
 

mygirls

Medical Marijuana (MOD)
whats a good way to lower my humidity other than getting a dehumidifier?
i used hyrdoton in the past with a flood setup. then i switched to soil with a sprinkler system.
pending on my weather out side i play with my freash air intake fan.either on, off, hi or low pending on what i need. if my weather is foggy and cold then i turn my intake of and that brings up my tempand lower my humidity.. when my temp rises itonly runs in the mid 80's. my exhaust fan running it still pulls air threw the intake fan
 

intche

Member
ohhh very nice, i usually just have my fan running the whole time. Im running a 1000w. i figure i run it full time to keep the light temp low
 

TheBoozer

Member
If you have good exhaust you should not need a dehumidifier unless your somewhere with high ambient humidity. Have you washed your room with bleach? Are your floors covered? If the mildew is in carpet or ventilation it be contaminating your plants.

I have dealt with powder mildew once. I bleached my room and killed off all the clones that came from plants with it. I had to completely start over but it has not been a problem since.
 

intche

Member
i havent bleached walls before. and only used a regular vac to clean the carpet. Im thinking i need to do a thorough job on cleaning
 

intche

Member
grow room is a box i built in my bedroom. i made a frame and used the black/white tarp to make walls.
 

maximum

Active Member
doesnt that powdery mildew piss you off? Me too. So I found in my experience its best to prevent it not fight it. What works for me is Mixing horticultural oil + baking soda+ dishwashing soap. (not dish detergent) For 1 liter water I put 1 teaspoon hort oil, and 1% baking soda and i teaspoon dish soap. This will pervent the pm from forming on your leaves. Also this mixture kills most bugs and prevents and kills lots of fungus and molds. Using more than 1% baking soda can hurt your plant.

http://attra.ncat.org/attra-pub/bakingsoda.html

Read about it there. It was an extensive 3 year study at cornell university. It works for me. I leanred the HARD way about using too much baking soda. Plants got stressed. So just spray 1 LEAF and wait 24-48 hours.

If you already have pm on there it may or may not kill it but it will STOP it from spreading. after spraying dump out your mix. it has no shelf life.
 

TheBoozer

Member
lights off all fans off. thats the way i role
I completely disagree with this train of thought. In flower if I shut off my fan during lights off my humidity will sky rocket to 80%. Your lights actually burn off humidity and when they are off humidity spikes. I run my exhaust fan constant when the lights go off.
 

mygirls

Medical Marijuana (MOD)
I completely disagree with this train of thought. In flower if I shut off my fan during lights off my humidity will sky rocket to 80%. Your lights actually burn off humidity and when they are off humidity spikes. I run my exhaust fan constant when the lights go off.
iyou must have a well seald room i don't.
 

27Bronco

Member
I have had good results with SM-90 as a foliar spray and PM, insects, etc. 1 part SM-90 to 5 parts ph'd water for insects and PM. only need a few applications. This is my trouble spray.

Then i use it as part of my regular foliar spray as a preventative measure. Remember tha SM-90 will raise your PH.

1liter ph'd water
5ml SM-90
10ml AN-B-52
5ml bloombastic (only during last 5 weeks of flower)
total ppm around 300
 

Desertfish

Member
I just recently had this problem. I used the baking soda method. It worked well but,I did burn a few leaves. I don’t have the PM problem any more. I took a few more precautions too. I trimmed that bottoms of all my plants (Lolly popped them) better air flow. And I picked up a dehumidifier for running during the lights out time. Two things that need to happen are raising the night time temps so they don’t fall below 72 degs. And lowering and keeping the humidity below 50%. Those are two things that will keep the mold from forming. So far so good.
 
Top