I have a 5ft x 8ft x 8ft tall room. Drywall construction. 2 Bestva 2000 watt LED lights and a visisun 390cfm carbon filter and fan unit. 28-45 %humidity, and 73-78 deg temp. I’ve been having white powder mold issues. Grow in Cococor 40 by promix and thoughts on what could be causing this?
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What kind of air movement do you have inside the room? 390cfm is really small for that size of a room.
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I have (3) 6in fans - one fan for each plant, plus a 200cfm 6in duct fan blowing into the room to increase intake of air. Was going to get a 16 in oscillating fan today to help.
Plants are in veg right now, in 5 gal pots, about 18 inches tall. Was thinking about getting an 8in carbon filer unit that has over 700cfm but didn’t know it that could be the cause.
Hey @420keppy what is your humidity at? I’m actually building a stealth grow box and I was told drywall is bad because mold can grow on it easy. I googled it and it says this. In using osd pressed wood and painting it will killz or something similar
Because drywall is a substance high in cellulose, it is one of the most common materials mold grows on in the home. As there is no practical way to completely remove mold from drywall , you will have to cut out and dispose of any drywall you discover which has mold growing on it.
Just a thought.
Hopefully this helps! 
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Humidity is between 28-45%, but usually on the low end I have to keep a humidifier in the room or the humidity is around 20%. I have a furnace duct blowing warm air in plus an electric heater when the heat goes down during the day or night with the programable thermostat.
I am not seeing any white mold on the plants in the pic you posted.
With humidity that low (too low) you shouldn’t be having mold issues.
White powder can coat things in the room…plant included from running a humidifier and hard tap water. As the water is vaporized there’s calcium etc in the water droplets and they will settle on everything and look like someone came through with flour and coated everything.
Is that kinda what your experiencing? It will also clog your charcoal filters pre filter as well as your furnace filter and will have to replace that more often as it clogs them and then your house won’t get to temps very well or run longer and sometimes it causes the furnace not to run due to restricted air flow. I now have an RO unit and only run RO water in my 4 humidifiers in my 2 rooms because that exact thing happened to me last winter. Was replacing furnace filter every 2 weeks and had normally been every 3-4 months for 15 years and the only thing that changed was running humidifiers with tap water for the grow.
Here is a chart for reference to help keep the relative humidity in check along with the temps and the stage of growth they are in and in future stages.
If you don’t think what I suggested above is going on please take close up pics of plants so we can see what your seeing.
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Depending on time of year here I will disable my programmable thermostat for house and manually adjust things to better control the environment in the tents but everyone’s circumstances are different.
If it’s from hard water and humidifier you’ll want to remove the pre filter from carbon filter and wash it let it dry and reinstall…
Also if your not in flower it’s not always necessary to hook up the charcoal filter to in line fan until it starts to smell in flower and that will both extend the life of the filter and help with temps if needed
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You’ll need an 8 inch in line fan to go with a bigger carbon filter too…
Many good options out there depends on budget. Some are junk…some are ok and some are great both fans and charcoal filters
Run your finger on anything in the room and if it picks up a chalky powder than it’s from humidifier and hard water
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Could be calcium deposits from the well water possibly. I’m thinking a bigger carbon filter would help with air exchange. Water is fairly clean, no iron but it does go thru a softener and then thru an arsenic filer media. I use purchased water for the plants.
Doesn’t look like mold issue to me but I can be wrong
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After reading your posts I think it’s prob the calcium or something left over from the humidifier water drying on the leaves. You may have hit it right on.
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I should maybe use distilled water in the humidifier.
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If that’s what it is and you don’t start using distilled or RO water you will keep running into issues. That’s why I bought a small RO unit for humidifier and now using that also for watering them as well.
May be less money over the long run…pretty sure it will save you money to get an RO unit and not have to buy water in plastic oil containers etc…
Hooks up to spout like a garden hose with adapter so won’t have to tap into water line and of course you’ll need to drain the waste water away.
I use a 5 gallon bucket and set my phone timer for 2:30 min and I’ll have about 4 gallons ready. Refill the old distilled water jugs and I’m good to go
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I’ll check into that. Looks simple
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It doesnt look like wpm to me. Consider yourself lucky.
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I actually had tap water ruin a 90 dollar humidifier. It got all pink inside and clogged up. I tried everything it just wouldn’t work anymore.
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That will be $19.95 worth of wisdom, make check payable to Diver Inc. I’ve seen this humidifier thing like 3 times now, maybe putting it outside the room as well then being filtered again before entering. Just talking out loud but WM blows and it’d be killer to hear that’s not the issue… good luck
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