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
Odin9
Plece help me to chose the best fan for the lover part..asap I most order now
Which fan sculd I go for in the lower part off tent??? I have det biggest 30w from secret jardin on top
Setup. Ventilation
5y ago
3
5
Solved
triforcepizza
When do I need to start using my duct fan for ventilation?
Should I be using my fan now, or wait until the plants get larger?
Week 1
Setup. Ventilation
5y ago
2
2
Solved
BullWeedDog
Utilizar filtro de carbono sin manga??
Puedo utilizar mi filtro de carbono sin la manga que trae para ponerle?? Es que al ponerla pierdo fuerza en el extractor y no se genera la presión negativa ya que él tuvo del extractor está doblado??
Other. General questions
Other. Other
Setup. Ventilation
4y ago
3
3
Solved
Bananito
How to Lower Humidity
The weather outside was really wet and chilly for days here and the humidity is about 60% at this point. Without a duct fan, how can I lower the humidity in the tent? I'm using several small fans right now. I plan to get a duct fan when I can, but I need something until then
Week 25
Setup. Ventilation
6y ago
3
4
Solved
Superjd
Overheat in tent? Measuring Correctly?
HID lights on seedlings day 2 (25 cm dist.) I was alarmed by temperatures rising since yesterday to 35 despite exhaust & small fan inside tent. Tent doesn’t feel overly hot. moving sensor to above light it reads at a good 26-27. What’s the best way to understand tent temperature?
Setup. Ventilation
6y ago
2
3
Solved
fuckitimhigh
Can an exhaust duct fan be too strong for a tent?
Can I use a fan with twice the capacity of what I need for the size of my tent?
Setup. Ventilation
5y ago
1
1
Solved
Herbinator
Can RH be raised to 100% for short periods of time?
My extraction is noisy and the humidity is causing a sore throat at night. Can I switch it off and raise my RH to 95% on a regular basis without stressing the plants? I have an indoor grow 2"x2" that runs full ventilation. RH rises from 70% to 95% after 30 mins of no venting.
Week 6
Setup. Ventilation
6y ago
2
Solved
MuMu_the_Grower
High humidity in the morning
I’m having a very hard time coping with humidity (goes up to 85%), since I physically cannot get the airflow outside my house for various reasons. I open the window each morning, but could it lead to rottening in the late stages of flowering? Thanks for your replies ;)
Week 9
Setup. Ventilation
4y ago
2
2
Solved
EXZELENS
Can I use a 100mm carbon filter on a 125mm exhaust?
So, the title is pretty straightfoward. I was thinkin about getting some 127mm extraction tubes and make it really tight to fit the filter. TIA
Setup. Ventilation
6y ago
1
2
Solved
Timmytoker77
19 days on 1st grow
This is my first grow. Bruce Banner. 19 days old. 28° and 52% hum Wondering if i got it right so far ????. Evening drops to 22° 80% hum. Any tips please .. Should i have fan or extraction on at all ???
Week 2
Setup. Lighting
Setup. Ventilation
5y ago
2
3
Solved
Arasari
Carbon filter life time
How long should a carbon filter last? Been using mine for 3 grows now and its starts to smell everywhere... any recommendations for a decent carbon filter?
Week 18
Setup. Ventilation
6y ago
6
5
Solved
Erasmus
Air flow method
I removed the hood from the home AC to run cold air directly into the grow tent with a 4 inch duct at the bottom. I have an inline fan to push hot air out to balance out the air pressure at the top. Is this a good idea or should I just have a fan inside with no in or out?
Week 4
Setup. Ventilation
6y ago
5
Solved
Ertomid
reduce humidity
What techniques exist to decrease humidity naturally without something made special for?
Week 5
Setup. Ventilation
3y ago
5
3
Solved
CreamOfTheCrop
Fan vs Fanless LEDs
How effective are heatsink LEDs? I'm not sure if I should go with fanless (like Mars Hydro SP150) or with a fan (Mars Pro II Epistar 120). I struggle with heat, when the tent is closed it gets to 29-30 degrees with humidifier in full swing (HID lights) and I want to close it soon
Setup. Lighting
Setup. Ventilation
6y ago
3
3
Solved
Newbiegrower420
Using humidistat to control fan, will this cause problems? So far fan running for 30 secs every two minutes! Plz advise if this is not a good idea??
My exhaust fan is to powerful no speed control just two settings. On the lowest setting the fan is still sucking all the humidity that my humidifier creates out of the tent. So I have bought a humidity controller hooked it up with the humidifier and fan.. It’s working great!!
Setup. Ventilation
6y ago
4
4
Solved
BigDaddyK
Humidity ?
When should I remove the top of the propagator ?
Week 1
Setup. Ventilation
6y ago
6
4
Solved
DaSofaSurfer
exhaust or ventilation?
during "night time" I can only have one fan. I'm undecided on how the one fan can better serve me. exhaust or ventilation? which is more important during dark. I do have a dehumidifier btw. no ac but atm temps have been cooperating. cheers guys, thanx in advance
Week 11
Setup. Ventilation
6y ago
5
5
Solved
Roope
Now have mushroom pack that makes CO2 so gueston is what is the ”best” hight? My plants are wery short By choise i want to make bonsai plants whit desent colas. So under or same line or???
Week 7
Setup. Ventilation
5y ago
2
1
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
ZigkGrow
Use my fan as exhaust or intake?
I have the door of the closet open and I have one fan. Is it better to use him as exhaust or intake ? I will install ventilation system after this grow.
Week 3
Setup. Ventilation
6y ago
3