How do I raise humidity in grow tent
- Thread starter shaunr97
- Start date
I use a small ultrasonic humidifier, and reduce airflow through the tent until the flowering stage.
you could use nappies , put it in a sink fill the nappy/ diaper with water until it holds no more water , cut open put the inside crystals into tubs on the floor , top with water when they start drying , have a little fan blow across the tubs , you can also get a misting bottle and spray the inside walls, but dosnt last long
How low?
Souptaco
Well-Known Member
Humidifiers are pretty cheap on amazon that’s what I would do. I have the opposite prob where I live
Drivejunky95
Well-Known Member
You'll want a humidifier that's at least 4L then play with different flap/vent arrangements in your tent or you'll be refilling it every 12 hours... lol
PurpleGunRack
Well-Known Member
Don't worry, mist the plants every time you pass the tent.
If it's really bad hang a wet towel in the tent
If it's really bad hang a wet towel in the tent
Growingasmile
Well-Known Member
you can get one of these for like 8 bucks on amazon
Growingasmile
Well-Known Member
same, literally just ordered a dehumidifier
Johnny5thesim
Well-Known Member
My issue with low humidity I think stems from outside temperature being cold and possibly too much air exchange in my tent. I added a bionaire warm mist humidifier. But it only added about 6%. I was getting down to 30% before adding it. Plants never seemed to care. And were totally healthy in that range.
Barney86
Well-Known Member
Keep the vents shut. Turn the extractor off, you don't need it for ages anyway. Bowls of water in the tent add a few percent too.
I live in New Mexico and we're lucky to get 20% humidity except during Monsoon season. I have a multi-room humidifier in my grow tent that can hardly give me 30-35% humidity in the tent. Are the ultrasonic humidifiers any better than mine?
My plants don't seem to mind the low humidity but I wonder how much of a difference more humidity would make.
Thanks
My plants don't seem to mind the low humidity but I wonder how much of a difference more humidity would make.
Thanks
I had a Bionaire humidifier that would put up to 25l (6.5 US gal) into the air daily. The Honeywell Ultrasonic Cool Mist Humidifier, HUL535 will evaporate only 1 US gal per day. You need to look at the specifications for what you have, and your proposed replacements.
Reducing the airflow until flowering, a small ultrasonic humidifier raised the humidity from under 20% to 40% in a 2' x 4' x 5' tent. It evaporated about 750ml or 3 cups of water per day. There was a heater in the tent. Between it and the light the temperature in the tent was raised about 10°C (18°F) over the intake air, which normally was at 18-20°C (64-68°F).
Note that increasing the temperature by 10°C (18°F) doubles the water capacity of air. Without the addition of water, this drops the rh by 50%. Similarly, dropping the temperature by the same amount doubles the rh. This is why the rh increases in your tent after the lights go out, until all the air has been exchanged.
Reducing the airflow until flowering, a small ultrasonic humidifier raised the humidity from under 20% to 40% in a 2' x 4' x 5' tent. It evaporated about 750ml or 3 cups of water per day. There was a heater in the tent. Between it and the light the temperature in the tent was raised about 10°C (18°F) over the intake air, which normally was at 18-20°C (64-68°F).
Note that increasing the temperature by 10°C (18°F) doubles the water capacity of air. Without the addition of water, this drops the rh by 50%. Similarly, dropping the temperature by the same amount doubles the rh. This is why the rh increases in your tent after the lights go out, until all the air has been exchanged.
Edzzed
Well-Known Member
What I did was get a 5 gallon bucket and filled it halfway with water. Then took a piece of coat hangar and draped 3 big wash cloths over it. I also have a small aquarium pump with a line and it has holes in it. One wash cloth holds it in place. I have the aquarium pump on a timer. Every 45 minutes it comes on for 5 minutes wetting the wash cloths. It is wrapped around the clothes hangar so it doesn't spray everywhere. Fan aimed at it makes for some good humidity. 4 inch extractor fan on a humidity switch comes on to lower humidity to 57 and then shuts off and repeats as needed. It works great and you can use my idea if you want. It's not patented. As for refilling water. I change it weekly but never had to add to it. You can see the pic and get an idea of how to rig it.
Wulves
Well-Known Member
I use a Vicks Vaporizer , a Holmes Cool Mist Humidifier and 2 of those Steam oil Diffusers without any oil , there tiny , cheap , can go 6 hrs long give off plenty of mist .
I have one on each side of my table , you can point your grow fans in a way to circulate the air just right.
My humidity is always between 55 to 66.
Barney86
Well-Known Member
Yeah it does make a big difference mate. I've been without a tent for the last 6 months and I hate it. Get a much better growth rate if you can keep it 60% during veg. I find sativa leaning strains don't like the low humidity more but it's not like it'll kill anything. Just don't grow as fast because they cant drink as much and leaves sometimes go a little bit wrinkly.
Thanks for the great info! I have an Aircare unit that holds 6 gallons that lasts 70 hours by their specs. I use anywhere from 2 to 3 gallons a day (24 hours). It says it will humidify 2700 sq ft !
I have a 4 x 8 tent using a 5 x 5 grow area with a LED light comparable to a 1000w HPS on a light rail. Anymore ideas? Get a bigger humidifier?
Thanks
What's the RH in your area?What I did was get a 5 gallon bucket and filled it halfway with water. Then took a piece of coat hangar and draped 3 big wash cloths over it. I also have a small aquarium pump with a line and it has holes in it. One wash cloth holds it in place. I have the aquarium pump on a timer. Every 45 minutes it comes on for 5 minutes wetting the wash cloths. It is wrapped around the clothes hangar so it doesn't spray everywhere. Fan aimed at it makes for some good humidity. 4 inch extractor fan on a humidity switch comes on to lower humidity to 57 and then shuts off and repeats as needed. It works great and you can use my idea if you want. It's not patented. As for refilling water. I change it weekly but never had to add to it. You can see the pic and get an idea of how to rig it.
