PM on my ladies

Need to get the humidity down in my grow tents and am looking at two types of dehumidifiers. One type is the cheap peltier style and the other much more expensive pump style.

I would like to go the cheaper route and use the peltier DH inside the grow tent. Have any of you reading this used one? If so do they really work on getting the humidity down? Mine is in the mid 60's and want to get it down to the 20's.

I know the room (pump) DH's work great but suck allot of power and are $$$. Not really concerned about taking the humid down in the whole room but rather just inside the grow tent.

Thanks for any advice or input you have!

Mr John

Mr John said:

Need to get the humidity down in my grow tents and am looking at two types of dehumidifiers. One type is the cheap peltier style and the other much more expensive pump style.

I would like to go the cheaper route and use the peltier DH inside the grow tent. Have any of you reading this used one? If so do they really work on getting the humidity down? Mine is in the mid 60's and want to get it down to the 20's.

I know the room (pump) DH's work great but suck allot of power and are $$$. Not really concerned about taking the humid down in the whole room but rather just inside the grow tent.

Thanks for any advice or input you have!

Mr John

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It depends on the size of your tents but better ventilation will lower hum. I can + or - by adding another fan, keep water buckets out of tent, and not watering plants as often.

I know that it's a common belief that PM can come from too much humidity, but PM is actually a airborne disease. I had problems with PM early on in growing and one treatment with a sulfur burner, it's never been back. All the sprays are shit but the Sulfur burner is a garuanteed fix.

Having said that, keeping your humidity down is really important, because if you think PM sucks, wait until you lose a crop to bud rot, it's the saddest thing ever.

But again, no dehumidifier, large or otherwise is going to cure your PM problems. Don't waste your money if that's what you're trying to fix.

https://www.hydroponics.net/i/101018

PM hates water, contrary to what everyone thinks. Powder and water do not mix. The name powdery mildew is not a misnomer. It obviously even does great at very low RH , low RH will not kill it. Like stated above, it's an airborne disease. It can really simply be dealt with by foliar spraying with high PH 9.5 water everyday. You can even spray flowering plants in the early morning or right when lights come on.

If you have a sensitive palate the sulphur taste will be present in the end product..

NW_Grower said:

I know that it's a common belief that PM can come from too much humidity, but PM is actually a airborne disease. I had problems with PM early on in growing and one treatment with a sulfur burner, it's never been back. All the sprays are shit but the Sulfur burner is a garuanteed fix.

Having said that, keeping your humidity down is really important, because if you think PM sucks, wait until you lose a crop to bud rot, it's the saddest thing ever.

But again, no dehumidifier, large or otherwise is going to cure your PM problems. Don't waste your money if that's what you're trying to fix.

https://www.hydroponics.net/i/101018

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purplelicious said:

PM hates water, contrary to what everyone thinks. Powder and water do not mix. The name powdery mildew is not a misnomer. It obviously even does great at very low RH , low RH will not kill it. Like stated above, it's an airborne disease. It can really simply be dealt with by foliar spraying with high PH 9.5 water everyday. You can even spray flowering plants in the early morning or right when lights come on.

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I thought the question was about how to lower humidity and not how to kill PM. Did I miss something?

Flash63 said:

If you have a sensitive palate the sulphur taste will be present in the end product..

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Duuuude, that is so not true. The sulfur treatment is something I did in my current room OVER TWO YEARS AGO! And still no PM. But yeah, it reeks like sulfur (sarcastic). Everyone is an expert on things they've never actually tried themselves. Do what you want, it's your plants.

Also, I believe the thread is titled "PM on my Ladies," so please forgive my assumption that PM was the problem looking to be solved? My mistake.

This is why I stopped trying to help people with what I always state is just my opinion. Then here come the experts who shit on everything anyone says with no grounds for their statement.

PM is an airborne disease, not caused by, but aggravated high humidity level.

The sulfur taste does not linger regardless of what some expert said. I would gladly put any crop in front of him with other samples from the club, and let him try and find the sulfur. Ridiculous.

As others have stated, lowering your humidity if you have PM in your area will not solve the problem, it actually thrives in low humidity. Do what you want but it will not go away by simply dropping your humidity. Not that it's a bad thing to drop your humidity, but it will not solve your PM issue, which was the original question. Also try and figure out your potential source of PM, I originally got it from bringing fresh air in from outside with minimal filtering, later found out my whole area is covered in PM, all outside bushes get it. Needless to say I don't bring air in from outside any more...

last year I grew zinnia flowers along side my pot plants...bad mistake as the flowers were prone to PM, which infected my pot plants.

anyhow, I used a home made cure that really worked well.

1 gallon of water
1 tablespoon of baking soda
1 tablespoon of vegetable oil
1 tablespoon of dish washing liquid soap

Mix the ingredients together and add them to a spray bottle.
Spray your plants weekly, preferably on overcast days (or just before lights out) to prevent it from burning the foliage.

I have been battling PM this entire grow. after 8 years of growing in the Seattle PNWet area, This is the first time I got pm... and I always pull air from outside.
I had left for a few days , came back and my grow roomwalls and ceiling was dripping with water because my exhaust ducting got disconnected and I had no exahuast out.

I then began my battle with understanding and dealing with pm to this day.
I understand its systemic. I did have outsources clones which might have had it. but I will never for sure no how I got it!
What should I do about harvesting? the leaves are coated but I plan on bathing them in H2O2. Should I just hold out or chop early?
. I use the Jorge Cervantes Youtube Powdery Mildew cleanse., it worked very nicely on my other girls. but its such a nerve racking thing to live with.

Amber, we live in the same city. I can not stress enough how effective a sulfur burner is. So effective, I've only had to use it ONE TIME, and I've never had it since. Hell, you can come borrow mine.
As far as harvesting goes, it's not going to be club weed. I don't know, that's a call every grower has to make for themselves, how much defects are still "acceptable".
I just made about 100 grams of hash today out of flower I deemed "unacceptable". No PM or anything, it just hermied on me.

Dr.Amber Trichome said:

I have been battling PM this entire grow. after 8 years of growing in the Seattle PNWet area, This is the first time I got pm... and I always pull air from outside.
I had left for a few days , came back and my grow roomwalls and ceiling was dripping with water because my exhaust ducting got disconnected and I had no exahuast out.

I then began my battle with understanding and dealing with pm to this day.
I understand its systemic. I did have outsources clones which might have had it. but I will never for sure no how I got it!
What should I do about harvesting? the leaves are coated but I plan on bathing them in H2O2. Should I just hold out or chop early?
. I use the Jorge Cervantes Youtube Powdery Mildew cleanse., it worked very nicely on my other girls. but its such a nerve racking thing to live with.

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Use a product called Seranade http://www.amazon.com/Bayer-Advanced-Serenade-Concentrate-32-Ounce/dp/B000FOKXBW You can control PM with other methods but, this will be the only thing you will need.

Greencure works good, Nukem works better.

I harvested this pm infected Pink Querkle today.
got a beast of a Blueberry Hills to follow sometime this week with the same disinfecting wash/rinse/dry process.

Thank you all for your advice and inputs!

Ok I learned something today from you folks that PM and humidity are not directly related. So, I will not purchase an expensive and not needed Dehumidifier..... thanks for that and thanks for saving me $$$.

Looking into the sulfur burner method. I have heard of it before but it has slipped my aging memory. I have tried Ed Rosenthal's natural fungicide spray and it did not help at all. I am afraid of the sulfur odor lingering and affecting the taste/flavors of my harvest. BUT I feel with the sulfur method it will kill all those nasty spores in my grow tents that I am sure are clinging to my fans/filters/lights/DWC buckets. This method should rid of all the spores and prevent reinfection.


Edit: OK damn them burners are expensive! 100 bucks or so. Anyone have a cheaper source or method?



For those growers that have had this does/did your PM only grow on leaves and stems leaving the buds alone? This is my case so luckily the PM is more of an annoyance than anything and wont ruin my harvest. I too live south of Seattle and like some of you for some damn odd reason have gotten PM this year and not in the last 2 years of my growing?

What is the deal with PM this year argghhhhh?

One of my ladies affected by PM that finished early was cleaned with the peroxide solution trick, kinda messy and needs a lot of space/fans I really don't have so ill probably avoid that method, though it looks like it worked well.

Thank you all and will keep updates coming.

For my outdoor plants a 1part fat free milk to 9parts of water spray worked well for me.

I mixed the solution, and sprayed heavily at sundown. This year I only applied once I think, and the mildew subsided on one plant and was kept at bay on the others.


Oh, yeah, sorry I couldn't tell ya how to lower humidity.

Lol maybe you should change the title lololol

Good luck buddy!

a senile fungus said:

For my outdoor plants a 1part fat free milk to 9parts of water spray worked well for me.

I mixed the solution, and sprayed heavily at sundown. This year I only applied once I think, and the mildew subsided on one plant and was kept at bay on the others.


Oh, yeah, sorry I couldn't tell ya how to lower humidity.

Lol maybe you should change the title lololol

Good luck buddy!

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Yea my title is a little confusing! Milk huh? gonna look into this after I hit my tents with the sulfur because I know I got damn spores everywhere and do not really feel like spraying liquids on my filters and fans and stuff. But I like the idea to routinely spray them ladies with the milk solution.

Thank you for your input!

I def want to do a sulfur burn after I harvest all these pm ladies.
Thanks NW GROWER,i appreciate your offer to loan me one because those are expensive for just one time.
MR. John, I know a dehumidifier is expensive but I think that its an essential piece of grow gear you really need to have. I pull over 50 pints of water DAILY from my Frididaire 50 pint dehumidifier. It cost about $180 at walmart. Its important to keep your humidity low during flowering to avoid bud rot, which I have gotten before as well.
Are you Seattle area growers aware of REGEN used grow equipment in Fremont? I have been able to purchase some reasonable priced / decent grow gear, including my tent there.

Dr.Amber Trichome said:

I def want to do a sulfur burn after I harvest all these pm ladies.
Thanks NW GROWER,i appreciate your offer to loan me one because those are expensive for just one time.
MR. John, I know a dehumidifier is expensive but I think that its an essential piece of grow gear you really need to have. I pull over 50 pints of water DAILY from my Frididaire 50 pint dehumidifier. It cost about $180 at walmart. Its important to keep your humidity low during flowering to avoid bud rot, which I have gotten before as well.
Are you Seattle area growers aware of REGEN used grow equipment in Fremont? I have been able to purchase some reasonable priced / decent grow gear, including my tent there.

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They are expensive, but it saves countless dollars in sprays and don't work... and milk.

I'm just gonna say Nukem one more time, cause that shit is the shit. But you got infected with PM, if you don't eradicate it completely it will be back. You are giving it a nice environment to thrive in and yes it will get into your buds and that is a pain in the ass to clean up. Fix the environment and have it well under control before you flower and the environment alone should keep it in check. But seriously Nukem is citric acid and wipes that shit out plus kills mites, and the dreaded broad mite if you should happen to get those. Greencure works the same way as sulphur by raising the ph on the plant material to a point where pm doesn't live. PM will persist with cuttings from plants that have it. I live just south or Portland, in the land of mold and mildew this is my first round using Nukem, no PM.