That’s what I’ve recently read, not recommended for aroma.
My situation…I shut down for the summer, my grow tent was home made, a trial run. I took it apart, threw away the Mylar and intend to build a slightly larger (lol, that’s how it starts) grow area next month.
I will run the ozone/ion generator in my cellar for as long as it takes before I start again.
@Paranorman , i use R.O. water i produce …it’s average ppm is 0-5 ppm …no plain well water any more …and i had it on the mothers that had originally been started in MG potting soil…and fed well water… then took clones ,for DWC … then cloned those for new mothers .and tossed the soil grown mothers out …and its starting to show on those only slightly now… but will get worse .as this is whats happening now …just hope i am close enough to finish them out .without it costing me too much in finish product …their still growing well enough , but with out this . It would be way better … need to fix before next run …seen the spot’s before on other strains …and i mean the little black circles around the minute hairs on the under side of leaves… cant see with naked eye, 16X only lets you see black specks ,thought it mitive been dust in past new micro scope showed it at 300X …in past had major probs maxing out cause of hard well water… now R.O. …but in the past plants looked totally typical cal -mag deffiecy yellowing in between the veins, .necrosis , edges of leaves yellowing ECT … but now only ROUND yellow dots on the veins … only when the leaves get real bad will it spread a little from the veins … iam thinking pathogenic virus ??? Hammer
@ kabongster it starts on lower older leaves mainly shade …i use R.O. water and use Avanced Nutriants …Connisour ph perfect A&B bloom ,now…silica, and big bud and hydrogaurd flush with peroxide water every 3 water change …leave in for the week then drain flush and use hydrogaurd …Could this be light toxicity ???
You could roll it up hill to a mentor, Donaldj (who said mildew or mold or environment?) or higher still…we are spinning your tires.
I’m just best guessing, ready to be schooled by a pro.
when I look at your close ups looks a lot like fungal which would explain why several plants and strains are showing signs not saying it is downy mildew but damn close and I would treat as if it were a mold or fungis milk and water spray apple cider vinegar diluted peroxide etc.
Thank you for your input @Donaldj the reason I am not sure about this is this sentence was taken from the link you posted above
“The pathogen needs high humidity in order to infect. Humidity often get above 85% at night outdoors but not in our homes, especially when we are running air conditioner”
When this first appeared my humidity was 30% or below on a regular basis for months (winter) and even now it’s monitored and regulated by an AC and humidifier, and seldom gets above 65%, even on the most humid days.
I’m not wrong in that my cheap yellow pH pen has been chronically off
What I thought was 6.5 pH was 6.2, I think eventually that I’m going to find out the cheap 10 or $15 pH meter is my whole problem
I still believe this is the source of these issues, as opposed to something more nefarious
I can only tackle one change at a time and see the result. Accurate pH readings are my change at this time
@Hammer this is where I’m at:
Flower = Ppm 900-950 (2 different GH flora mixes, both include 2ml GH cal-mag)
pH = 6.5
Veg = plain pH 6.5 in ffof soil, & GH Flora ‘mild veg’ strength nutes + 2ml cal-mag/gal. every other feeding
So at this point we seem to have the same thing, although I have little in common with you, we use nothing the same and you live thousands of miles from me, so that’s what we got so far …hummm
Am under the weather rite now ,so am slow on internet searching …And replys .sorry .how much lite you throwing on the girls??? … iam using 1800 watts and using the boost mode on my ballast how close is your lite to canopy …and half of my room is 3 ft from tops and the other side is 18-24 inches … but don’t think that is problem .Gonna chew it for awhile to see if i can solve our problem…
Donaldj be very careful using this …i use white vinegar and peroxide solution …to eat LEAD of of Stainles Steel gun barrels …It dissolves the lead … i realize that an acidic kills mildew… if mixed FULL STRENGHTH IT WILL FRY THEM girls Hammer
I think we can also eliminate light. It starts under 400 or 600w in veg long before it hits the 1000w flower tent ?
Feel better hammer I got a couple of ideas I want to run by you honestly I’m just reaching out in the dark here but I’m not ready to believe it’s some kind of a strange virus or fungus yet
I believe it’s pH induced and I’ve got a couple ideas when your feeling better.
take care of yourself! I had the flu last week lasted maybe 3 days, one day was real bad
Four OG Kush, 3rd generation, both prior Generations have had it, but this is my most resistant plant. if I can keep it from appearing on these four than its a pH issue ? …isn’t it? Lol, we’ll get this!
Me: I just got back from Africa, I was playing cards with the natives
You: Zulu’s ?
Me: no, I usually won !
yes i know , are you any good with putters??? me iam still learning what all the forum icons do …only figured out how to "quote folks recently …lol But I can google .
and maybe a few of these 
lol
I’m not ready to ascribe this to anything but a misbehaving pH meter yet
I would ask but I’m assuming you’ve got a pretty good meter there
It shouldn’t take long with the new meter and what-have-you and recording stuff and all that happy shit that I don’t usually do
…if these four OG clones get this then I am officially going to put my hands in the air like I just don’t care and surrender
Then I’ll start spraying milk …or drinking it (or both)
I just am not ready to believe this is something mystical and magical, a virus, a blight or a generational curse ! Nope I believe it’s a malfunctioning meter and I’m staying with that for now
@Hammer here’s what I’m thinking
…in my case my pH was always about 6.2 sometimes when it said 6.3 that means it’s in the high fives so what I’m thinking is that I’m slooowly locking out all or some of the micronutrient that needs a higher pH for proper absorption
I believe it’s chronic and I believe that’s why this shows up at around the same point and around the same time in all plants that are cloned and kept together (same mother)
I think some get it worse than others because some get a lower pH. Admittedly I’m not all that careful but now with the new meter I’m dead on and recording everything
I’m going to get to the bottom of this hammer either you or I or somebody here is going to help us with this.
… this is not simple thing but we can solve this my friend, feel better and let me know what you think about this Theory
iuse two ph meters but the one i faver is the eco green one it reads fast and has stayed accurate …i test it before every use it takes about a second …to do i also use tds meter for my ppm …in hydro mine hits on 6.2 st h2o chang then i let it drift down to 5.6- 5-5 .max then rais it again …this allows it to absorb more nutes …when its in the 6.2- 6.3 range it get more nitrogen at the lower end it aborbs more P&K … am going to the link you provded … got to read it …Hammer
@Paranorman i think you may have it NAILED DOWN …i have to join to post … are you a member there??? is so can you post the picts of my underside leaves … and ask if theirs look like mine … 90 % of those photos are perfect spot on of mine …and did you see where they mentioned the OG kush as being a very resistant strain to this fungus but that their Cheese was croaking 
Hammer . I.See no ghost in the machine …and this is a very wet year here its adding up …NOW where do i get a fungus BOMBs for my room .spaying for that in my room is not feasible …Hammer …
@Paranorman … wonder if burning Sulfur in the room would help ???or i may have to start taking down early …gosh i hope not …as i have 2-3 weeks left and their just starting to Pump It Up … lol Hammer … see the black spots do remind me of a fungus …makes sence …but got to take it up a notch now …and prove it …first is hypothesis,.then, theory after that its fact …Hammer .iam gonna go breath and drool on them for a while oh yeah and stare at them as if at beautiful women 
Hammer… Back in saddle soon… i soon want to start a new thread soon …maybe… First need to search the forum see if i can find something on the subject frist …if not then ill start it …How To Clean Seeds … to prevent bug or infections … to avoid cross contamination …maybe order the OG strain as back up LOL
Yep at least I feel pretty sure that we identified it, now comes the nightmare 
Like you said about the pictures I’m pretty sure that it’s ‘spot-on’ (bad pun)
Edit: my og kush mother had none. Two of her four clones has minor symptoms (2nd generation) and four 3rd Generation clones has none yet, but they’re only about 8-10" tall right now, but the cheese was not so lucky
Cheese mother has issues but she’s also got about 3 ounces on her short stinky little frame so… cheese clones still look pretty good, two have some, two look pretty good so far…
So… here we go !