Hi there. I'm running 20/4 cycle. When my lights on my humidity is at around 40%. I've just turned my light on after the 4 hours of the light being off and the humidity had risen to 73%! I'm growing 2 autos and I've got a photo seedling in there. I understand the chemistry to why it happens but whilst I haven't got a dehumidifier should I just run the lights 24/7 so the humidity doesn't rise or will no darkness have a negative effect?
Humidity problems
- Thread starter Deantrfc
- Start date
Hobbes
Well-Known Member
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Is your photo in the veg cycle? Plants need rest too, 24/0 would be hard on them.
I run a dehumidifier in my house for my entire grow, I take about a gallon and a half of water out of the air every day. I recommend one.
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Also, I'd recommend a temperature/humidity switch for your exhaust fan. I have mine to come on at night if the humidity gets above 50%.
HT-2 Humidity Temp Controller
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Is your photo in the veg cycle? Plants need rest too, 24/0 would be hard on them.
I run a dehumidifier in my house for my entire grow, I take about a gallon and a half of water out of the air every day. I recommend one.
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Also, I'd recommend a temperature/humidity switch for your exhaust fan. I have mine to come on at night if the humidity gets above 50%.
HT-2 Humidity Temp Controller
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Yeah the photos only a seedling. I'm going to order a dehumidifier but with what's going on it'll take a week or so. I'm just thinking of a way to decrease the humidity when my lights are going off for the moment. One of my autos is definitely in flower but can't see any pistils on my other one yet
Run your lights 24/0 in veg. I've been doing so for eight years since I started growing indoors. You will absolutely have to get a dehumidifier before you go to flower though for certain.
Dontjudgeme
Well-Known Member
Your only option without a dehuey is to crank up the speed of your exhaust. That way it’s sucking all the humidity out. But if your outside humidity is high as well, that could pose a problem because all you are doing is bringing that humidity right back into the tent. If you have sufficient air flow, you shouldn’t have an issue with mold. Stagnant air is a recipe for disaster.
2Hearts
Well-Known Member
I see no humidity stress or growth from high humidity.
It seems like your humidity is high where you live and seem to be putting the humidity meter in or on the light as such a large swing seems not environmental.
Just an open window somewhere and an inline will deal with humidity, lowering it would required a sealed grow or room which is highly problematic. Humidity is a problem in still air not really in moving air so you can grow in higher humidity just like plants do in the wild if they have adequate ventilation so humidity dosent build round the bud or leaf.
It seems like your humidity is high where you live and seem to be putting the humidity meter in or on the light as such a large swing seems not environmental.
Just an open window somewhere and an inline will deal with humidity, lowering it would required a sealed grow or room which is highly problematic. Humidity is a problem in still air not really in moving air so you can grow in higher humidity just like plants do in the wild if they have adequate ventilation so humidity dosent build round the bud or leaf.
I always leave my exhaust fan on, tents always negative pressure when zipped up so still air shouldn't be a problem. It's only 2x2 so haven't bothered using an intake fan I thought my exhaustion fan would move the air about enough. If I put a small fan inside the tent just pushing the air up towards the exhaustion fan when lights are off do you think it'd lower humidity?
I'm going to order a dehumidifier this week. My tents only 2x2 so should I just get the smallest one possible? It's only for 4 hours a day. Has anyone using a 2x2 tried them dehumidifier crystals? Just thought with such a small tent the less space being taken up the better so if they work it'd be ideal
FADING-SILHOUETTE
Well-Known Member
Keep your exhaust running when the lights go off, crack a window open for air exchange ..or speed up the exhaust...also exhaust out to another room etc... - STELTHY 
I keep my exhaust running 24/7. It hasn't got an adjuster on it, it's only a budget one but for my size tent it does the job for now, well whilst the lights are on anyway. With my tent being small I have the exhaust fan inside and my carbon filter is literally right next to my tent. Should I move it as far away as possible? I always have a window open in the room that the tents in. I'm going to upgrade my exhaust fan eventually but it's my first grow so I just wanted to get everything togetherKeep your exhaust running when the lights go off, crack a window open for air exchange ..or speed up the exhaust...also exhaust out to another room etc... - STELTHY