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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
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Selected By The Grower
Similar Grow Questions
Solved
Luna91
2200w LED
Hiii I got two LEDlamps 2200w in total but can’t use their max power cuz the temperature will be over 37soon! In order to cool down the tent I’ll need a true AC or a powerful fan, both of these products in photo are dehumidifiers as well, that 80€fan will cool ⬇️? Cuz im on budge
Week 5
Setup. Ventilation
5y ago
1
2
Solved
masdefs33
Tried mini dehumid. still issues with portable ac (added @ 9pm 6/2) see pic for graph
Avg RH was 45%,had spikes @ 80% RH in dark, added portable ac to my tent. It raised avg. RH not lowered. Intake @ 40% RH that runs on a humidity cont. set @45%Now Day RH ~52%, Night RH ~60%.Ac starts RH spikes to 70% in dark. WTF am I doing wrong. Id hate to lose it to mold.
Other. General questions
Setup. Ventilation
2y ago
5
Solved
TeeAychCee
Best way to cool your tent/ growbox?
So I’ve built a custom growbox using an IKEA wardrobe, air vent for intake, two circulating fans, carbon extractor exhaust, and a 600W LED grow light. Temps average at 29 degree Celsius with the lights on full, is this too high? Best way to bring the temps down? Many thanks!
Setup. Ventilation
3y ago
2
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Solved
AccidentalB
High RH in flower
I find it really hard to keep the RH below 50%, especially at night when temps are low. I have a dehumidifier in the room where my tent is in but even when it's below 50% there, it still is above 50% in the tent itself. Can somebody explain this? Probably help me with a solution
Week 14
Setup. Ventilation
3y ago
1
1
Solved
GodOfAnger
ventilation for a 4x8 ? basically is that too much negative pressure and if so should I get anther intake ?
currently using a 200mm inline exhaust fan that has 914 m3/h(537,9 cfm) max currently using it at its medium setting of 792 m3/h(466,15 cfm) and using a 125 mm inline intake fan with only 330 m3/h (194,23 cfm). Should I get anther intake fan or should I put the exhaust to low 680
Other. General questions
Other. Other
Setup. Ventilation
2y ago
1
2
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
5y ago
3
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Solved
XanHalen
This is windburn right?
This is windburn right? left 2 fans on for 48hr, when I usually alternate between them each day.. Anything i can do to help recovery? should i have fans on a timer to give some fan downtime?
Week 4
Leaves. Wilting
Leaves. Other
Setup. Ventilation
5mo ago
8
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Solved
Donkeybuds
Air con unit
I have 8ft x 8ft insulated room I want to remove the intake and exhaust fan due to noise. I want to run air con unit for heat and cooling may be co2 bottle would this be ok
Setup. Ventilation
5y ago
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Solved
Hou_Stone
Hello m'y room is 100x100x200 cm If I put a 150m3/uur fan as in the photo is this sufficient as an air inlet? I have an adjustable 400m3/ur extractor with carbon filter in the room
Setup. Ventilation
3y ago
2
2
Solved
DrCris
Is a fan nessesary?
Do you need a fan if you have a carbon filter with ventilation installed ?
Setup. Ventilation
5y ago
3
3
Solved
kaladoum
Ventilation
I just have one plant under a small grow tent. But I haven't set up a ventilation system that looks a bit complicated to me to install. Is it possible to function without if I open the grow tent wildly once or twice a day to change the air ? Or will I be in trouble ?
Setup. Ventilation
4y ago
1
3
Solved
Newbiegrower420
Humidistat levels vary wildly between Inkbird and ETI humidistats..
I have two humidistats, one is an Inkbird 200 for control, the other is ETI 810-195 just for display.. The ETI is showing roughly 9-10% higher humidity levels compared to the Inkbird. Does anyone know which is more accurate? I want it get these humidity levels just right 👌🏼
Setup. Ventilation
5y ago
2
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Solved
Lovni
Problème humidité
Je n'arrive pas à stabiliser l'humidité. J'ai arroser les parois de la tente lors du dernier Arrosage qui aura une solution pour garder une bonne humidité et que humidité sera idéal pour la suite ?
Week 3
Setup. Ventilation
4y ago
2
1
Solved
Newbiegrower420
Cooling whilst using humidifier outside a small grow tent
I have a small 90x90x60cm grow tent with a VIPARSPECTRA 300W LED. Heat levels are crazy and running a small humidifier with ice blocks inside the tent along side extraction isn’t cutting it. Could I buy a bigger humidifier, keep it outside the tent duct it in to keep it cool?
Setup. Ventilation
5y ago
4
10
Solved
HerrTom
Brauche ich unbedingt einen (Schwenk-) Lüfter in meiner Growbox?
Habt ihr schon mal ohne (Schwenk-) Ventilator in der Growbox angebaut? Wenn ja, welche Erfahrung habt ihr dabei gemacht? Ich möchte nur ungern einen Ventilator einsetzen, weil das vermutlich die Lautstärke der Box deutlich erhöht. Schon mal vielen Dank für eure Erfahrungen.
Setup. Ventilation
1y ago
9
8
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
5y ago
3
3
Solved
Buddy_Bloom
tent pressure
i have a positive pressure in both tents because i have an AC plugged on my intake to manage the temperature inside the tent easier. Can it be a problem for my grow?
Week 3
Setup. Ventilation
4y ago
2
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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
2y ago
4
Solved
ForTheMeds
Airflow for seedlings
Should i have both fans on in this stage?
Setup. Ventilation
5y ago
1
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Solved
jokgga
Mycelium or Fungus - Too much?
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Plant. Other
Setup. Ventilation
5y ago
1
1