Mold :(

hi there, ive recently changed grow room and my plants had such bad mold i had to kill them.

here is what i have

a brick built shed, fully sealed and waterproofed,

600watt light
small office fan inside
100mm hole for fresh air (nofan)

do i need to introduce some sort of fresh air? it does seem very humid in there!

im from england btw and i do have a heater in there

If you have the budget cut another 100mm hole away from the first one. Install 4 inch flanges on each hole. Hook up 4" fan to each flange, one for intake and one for exhaust. Hook a hepa filter up to the intake and a phat filter up to the exhaust. Hook them up to a humidity control and set it to 72 degrees and 40-50% humidity so your room will bring in fresh cool air to keep your room at optimal conditions. Do you live in a cool climate? That makes a difference in room setup.

Just like our bodies, the plants also need fresh air to breath. Without proper ventilation your plants will suffocate. They need basic elements to survive; Water, Food & Oxygen...

And if it's really humid in there, then buy a small dehumidifier, cause that's where your mold issues come into play, especially during flowering.

Logan Rhodes said:

Just like our bodies, the plants also need fresh air to breath. Without proper ventilation your plants will suffocate. They need basic elements to survive; Water, Food & Oxygen...

Click to expand...

Not entirely true. I have a friend who has a completely close environment that has no intake and no exhaust. He has 4 air cooled lights in a 10x10 tent that are receiving massive amounts of cool air so the lenses are actually cool to the touch. He uses c02 enrichment and a sniffer and controller to keep his levels at 1600 ppm. They never receive fresh air except when he opens the tent door to check on them once a day to every other day.

I originally called bullshit on him and eventually got a chance to check it out. His yields and quality blow away anything I've ever seen in real life or on the internet. He's pulling around 10lbs every harvest off 4 lights. Since he's not having to exhaust cool air to cool the room he's not exhausting and wasting all that precious c02. His humidity is higher than I'd like mine to be, always floating around 65%, but he has a pretty mold resistant strain and hasn't run into any bud rot yet.

Logan Rhodes said:

And if it's really humid in there, then buy a small dehumidifier, cause that's where your mold issues come into play, especially during flowering.

Click to expand...

What small dehumidifier have you found that will be good for a small room around, 8x4 feet? I have tried a couple from sears and one from bed bath and beyond and they all sucked. And I don't have room for a large one.

Yes it is ENTIRELY TRUE............your mates room isnt as sealed as you think, or there is some bullshit he's feeding you that you've missed
With no fresh OXYGEN to roots theyll suffer. Opening a door would not normally providing enuff oxyen unless he's in their all the time.
So he IS getting fresh air in...
Try a sealed NO INLET yourself. Won't take too long to see the damage it causes.
Why don't YOU sit in a sealed room and see how long YOU last

Hillcrest said:

Yes it is ENTIRELY TRUE............your mates room isnt as sealed as you think, or there is some bullshit he's feeding you that you've missed
With no fresh OXYGEN to roots theyll suffer. Opening a door would not normally providing enuff oxyen unless he's in their all the time.
So he IS getting fresh air in...
Try a sealed NO INLET yourself. Won't take too long to see the damage it causes.
Why don't YOU sit in a sealed room and see how long YOU last

Click to expand...

I won't argue here. I don't get it either. He told me that c02 enrichment is the key. Maybe because plants convert c02 to oxygen? I honestly don't know. I just know what I saw. All the vents on the tent were zip tied off around the cords and the plants were doing great. If I could try it I would but I don't have the ability to be lugging c02 tanks in and out of my place, or the climate for it.

AH a tent...... it aint sealed then simple as that. Yes plants breath out oxygen but I very much doubt your friend has created his own microclimate/enviroment that can maintain itself IN A GROWTENT. I'd be supprised if ANYONE on here as EVER done that. Unless they work at the Eden project
The term sealed is banded around quite alot on here, it seems sealed on RIU means got holes in.... take the first post in this thread for example.....
eg. the shed is waterproof and sealed....... erm how's it sealed with a 10cm hole in it

Sheepy...
As stated above.... fan in ..fan out... I'm in UK and that should sort ya.
Dehumidifers in a shed in UK.... aint going to dehumidify anything unless it's massive as you'll be pumping in damp air anyway.
The humidity WILL decrease soon as fans sorted.

I have only had mold once, and it was on a Northern Light indica that had an extremely dense main cola. Not sure what strain you are growing, but it might be better to grow a strain that has multiple smaller buds instead of one huge dense one.

I wasn't able to catch my mold problem as soon as I could have, but I was still able to save the lower 2/3rds of the plant. If I would have paid closer attention - I saw the problem three days earlier, but my bright HPS kept me from investigating soon enough - I would have been able to salvage more of the cola I cut off. This is one of the more depressing problems you can encounter. I have grown lots of White Widow and never had mold problem with these.