Check the winners The Grow Awards 2026 🏆
Start My Diary
Start My Diary
Log In
Start My Diary
Home
Diaries
Strains
Shorts
Questions
Contests
Growers
Seeds
Breeders
Nutrients
Equipment
Blog
English
Log In
Sign Up
Following
Follow
Brands
&
Growers
to get updates
Back to Grow Questions
fan from bottom
koronkonko
started grow question 5y ago
Hi! is it a good idea to blow fan from bottom to plants? Of course i have a fan with carbon filter on top of the box.
Solved
Setup. Ventilation
likes
Louder
answered grow question 5y ago
I run one that blows over the top of the soil and another over the canopy. Don't see an issue with what you're doing
likes
Complain
Selected By The Grower
Similar Grow Questions
Solved
Newbiegrower420
Slowing a two speed inline fan
Can I run a fan speed controller with a dual speed inline fan? My 4” two speed fan is slightly too powerful for my grow room. I’d like to slow the fan slightly but I have heard the these types of controllers don’t work with two speed fans? Any advice or what to buy to do the job?
Setup. Ventilation
6y ago
3
3
Solved
EthosMultipassMemberRovairok
How to automate everything?? Help!!
Okay what do I buy to regulate the temp on the ac there's no thermostat on the window one. Like what do I need to buy now to auto all this shit ?????? 10 amp 1200 watt 5000 btu lil guy
Week 7
Other. Other
Setup. Ventilation
6y ago
6
6
Solved
RichBud5
Now getting condesation in my tent when I've added this duct to a pipe exiting the house? Am near harvest too.
Didn't have an issue with condensation inside the tent before, now that I've attached the duct to a pipe going out i'm getting condensation inside... Does the set up look right? I've hooked up to a smaller tent too via a T. Could it be pressure?
Setup. Ventilation
5y ago
3
2
Solved
TheColonel420
Mold and powdery mildew
Hi everyone. I have seen some of my friends suffer with mold issues in their grow tent. How can i keep mold out of my grow tent? Thanks My set up during this winter is to have the extraction fan off with a fan pulling in fresh air into the tent. P.s. i do not have any mold yet
Other. Mold
Setup. Ventilation
6y ago
2
2
Solved
alhambra
Temperature Probe. Where to place it?
I use a Vivosun exhaust and control hub. It comes with the temperature and humidity probe. I am curious, based on experienced growers here, where do I place this probe? On the floor or do I let it hang mid-way in the the plant itself?
Setup. Ventilation
3y ago
4
Solved
ganzigunnu
Dealing with hot summer
im experiencing 32 degrees celcius it's middle way through flowering. do you think it's too bad or does it reduce my harvest significantly? what happens if i switch to 12/12?
Week 7
Setup. Lighting
Setup. Ventilation
5y ago
2
2
Solved
STAYINGONMYMAINCBATORUNTWO
Heat
I’m thinking of putting a 12” fan up high to move the air to one space and an extractor to take out the air and a second cooler as I got up to 30c on a day of 15c so need some measures! Question is will it work? Don’t want to waste time on pointless things!
Week 2
Setup. Ventilation
6y ago
5
5
Solved
EthosMultipassMemberRovairok
Good
[email protected]
What's a good dehumidifier for around 300 or so I can't tell what's shit or what's good? Tr hat all say the same shit
Other. Other
Setup. Ventilation
Setup. Other
6y ago
1
Solved
TripleCcannabis
Low humidity issue
Tents 20'' × 30''. Using a vivosun 6'' inline fan to exhaust with passive intake to create negative pressure. I have a good humidifier but even on full the rh doesnt go above 40%. Not unless the room the tent vents into becomes super humid as well.
Setup. Ventilation
Setup. Other
6y ago
1
4
Solved
Hou_Stone
air inlet ?
I have a 100x100x200 cm chamber with a 205 CFM extractor. But I don't understand what is needed for the air inlet. leaving a hole open at the bottom with nothing is enough ?
Setup. Ventilation
3y ago
4
Solved
Ema26
What’s up guys me again😂 I’ve got my hps up and running and I’ve got the temperature under control by having my fan blowing directly at the light and I’ve added a oscillating tower fan. How can I keep the temps up when lights go off? Many thanks!
Other. Other
Setup. Lighting
Setup. Ventilation
6y ago
3
5
Solved
ChopperMcOG
So has anybody used these cordless mini dehumidifiers in their grow rooms? They’re small units that u charge over night every so often when the silica changes colour? My grow room is very small so an electric dehumidifier wouldn’t fit and I’m struggling to keep humidity down
Setup. Ventilation
6y ago
1
2
Solved
BooBoosHotBoxCornGrow
Temp tent issue
Nice! Thanks guys for the quick help! I’m also kinda sort of having a temp issue, I’m trying to make it the best I can, I’m way down south and the temp reads 86-88 a lot. If I blast the fans and humidifier it does get down but I’m worried about the electric bill going up.
Week 1
Setup. Ventilation
6y ago
3
3
Solved
TheNextGanjaMan
High humidity
Hello. Even with a dehumidifier and a 24-hour extractor, the humidity is still above 70% and one of the plants is almost in the flowering period. Can I add expanded clay on top of the vase to see if it lowers the humidity or putting more perlite will solve this? Thanks.
Other. General questions
Setup. Ventilation
4y ago
3
Solved
Eagers
Seedling Air Circulation
Im growing seedlings indoors in a window (they are only 7 days old) but ive been wondering at what point do the plants start needing circulating air? Found limited answers online, they will be going out to greenhouse once theyre big enough but for now do they need a fan?
Week 1
Setup. Ventilation
6y ago
4
5
Solved
Foggedaboudit
Do air extractors fit with any grow tent or do they have specific sizes?
Setup. Ventilation
3y ago
1
1
Solved
Debutant_dream23
Extracteur et intracteur
Salut j'aimerais partir sur la gamme cloudline Ac infinity ! Ma configuration :tent 4×4! 120×120×200! led:800w ! quel type d'extraction en sortie et en intraction d'entrée d'air me conseillez vous ? Je me suis renseigné sur les différents calculs mais en vain éclairé moi 🙏🏻🙏🏻
Setup. Ventilation
5y ago
2
2
Solved
NoBammerWeed
Extraction and ventilation of 1.2x1.2x2m tent in bedroom.
Hi, trying to refrain from cutting a hole into ceiling for extraction, can i suffice with the extraction ducting directed to an open window? will this 'mix' the tents expelled O with enough fresh CO2 for passive intake? 1.2x1.2x2m tent, 600wHPS aircooledhood, 4"RVK, PassiveIntake
Setup. Ventilation
6y ago
4
4
Solved
PortkeyCannabis
Humidity
I’ve been seeing a lot of people have a much lower humidity. I’ve been keeping mine at 75-80 with around the same temps. Is that to high?
Week 4
Setup. Ventilation
4y ago
1
1
Solved
Nurse
dehumidifier
there is a space of 1.20 by 1.20 m with a height of 3 meters with a humidity of 75 & a temperature of 23 degrees.I have to increase the humidity to 40% for 4 autoflowers.What size dehumidifier should I buy?
Setup. Ventilation
6y ago
1