By continuing to use the website or clicking Accept you consent to our cookies and personal data policy. For details please see Privacy Policy
Accept
Negative pressure?
Kitties_and_Colasstarted grow question 2 years ago
Hey Grow Fam!! Could anyone explain to us why negative tent pressure is a bad thing? We always have a little bit of a pucker, but our spare exhaust is way too big for a 3x3, even on low..thanks for any input friends! Question theme: www.youtube.com/watch
like
AsNoriuanswered grow question 2 years ago
Your target is to get very small negative, then 100% all smells go away.
I think too big is related to absorbtion and waterways, but I am a heavy smoker, from many videos, books and articles I know one - my target is small negative pressure and I follow it, works great I think ;)))))))
CRiSPrGrowanswered grow question 2 years ago
negative pressure is totally fine, but basically it simulates different altitudes, and this affects the VPD charts. with less pressure you need less moisture or temperature or something to get it right, but it's like that : since we dont know there s a drop in performance. dial it in correctly and it's really no big deal. The easiest is to play with the humidity and see for yourself . learn more about VPD and how it controls metabolism here : https://pulsegrow.com/blogs/learn/vpd Hope this helps ! 🚀
1 like
Complain
Similar Grow Questions
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
a year ago
4
Solved
Ertomid
reduce humidityWhat techniques exist to decrease humidity naturally without something made special for?Week 5
Setup. Ventilation
a year ago
5
3
Solved
MontyGrowz
Why is my RH so high?Inline Fan: S&P TD-350/125 Silent (in use) AC Infinity CLOUDLINE T6 (not in use, but testet)
Filter: Can Lite Filter 300m³/h
Transformator: SCNR5 (in use on setting 4/5)
Tent: 2x4x6 ft, i get 70-80%+ RH inside
My Room is at 45-50% RH with a temp of 60-70°F. Old Air gets outside.
a year ago
2
2
Solved
masdefs33
Tried mini dehumid. still issues with portable ac (added @ 9pm 6/2) see pic for graphAvg 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
a year ago
5
Solved
alhambra
Exhausting air outside when using Air Conditioning, yes or no?Hi there. This is my first indoor grow in soil. I have a room with A/C. The grow tent is in that room. My question is, should I be exhausting the air from the tent outside or into the room. If i exahust the air outside, isn't it counter productive to the A/C?Setup. Ventilation
a year ago
3
3
Solved
Hou_Stone
it's getting too hot. I added 2 fans inside. Do you think I can enable them 100% of the time/all day? Or is it bad for my plants?
Week 11
Setup. Ventilation
2 years ago
2
1
Solved
Lordcrow
I am facing a temperature problem again....My tent reaches 84.2F, which is too hot in my opinion. But my humidity is perfect. On the other hand, if I activate the ventilation, the temperature of the tent reaches 76F, which is perfect, but the humidity level drops dramatically to 35%.
1- Keep Humidity
or
2-Keep TempWeek 1
Setup. Ventilation
2 years ago
4
5
Solved
MiyaguiOkPolilla
Demasiado calorEs posible que la lámpara CMH se calienta demasiado debido a las horas que lleva de uso? 🔥🌱
Anoche llegué a casa y me encontré con este panorama, algo con lo que no puedo lidiar ya que tengo 2 extractores y 2 ventiladores funcionando todo el tiempo ⏲️
Setup. Ventilation
2 years ago
1
2
Solved
Gazeye
Risk of bud rot with these conditions?My tent keeps bouncing between 55-65% throughout the day during mid-late flower stage. Staying between 24-26 C. I have two fans moving air in the tent and the plants are we defoliated. An in-line fan is pulling air out. How much at risk am I for bud rot? Thanks!
Buds. Other
Setup. Ventilation
a year ago
2
3
Solved
VitaMan
Peltier dehumidifier @300ml per day adequate for 3x3x6 tent? Alternatively, a conventional dehumidifier outside the tent?Peltier thermoelectric dehumidifiers extract 300ml of water per day. Weak compared to compresser units, small and use less energy. Is it enough?
Would a conventional dehumidifier set outside of the tent near the intake be effective, or does it need to be inside the tent to worka year ago
2
2
Solved
DFWmd
Dehumidifier recommendationsAny recommendations about a dehumidifier for the 4x4 grow tent? I think even with vacuuming run-off more frequently, I won't be able to get humidity consistently down below 60%. Amazon has some in the 45-90 USD range...Other. General questions
Setup. Ventilation
a year ago
2
3
Solved
Melacola
HumiditéHumidité varie pas mal et j ai investi humidificateur mais sa ne résout pas le souci ventilateur 2 et deux entrés passive mais je pense trop de plans et je suis dans un endroit sous sol merci bien à vous l humidité n est pas bonne pour la floraison
Week 8
Setup. Ventilation
a year ago
4
5
Solved
NonameGrowDude
grow tent / lung room temps???Dialling in my tent and want to compare to others to see if more ventilation = lower temps.
What temperature and humidity difference do you have in your tent and "lung room"?
Do you exhaust your air from the tent to the outside of your lung room?Setup. Ventilation
a year ago
1
Solved
Prilyfe13
How do I drop my RH down when nothing works? Check Diary. Will defoliation be a good idea? Open tent door and leave it open?My 2x2 is starting to crowd. This is driving the RH to over 70%. Should I defoliate to help with crowding and RH? Or should I just leave it alone? RH in lung room is 48% Exhaust fan, high or low with a dehumidifier, doesn't work. What should I do? Defoliate? Thanks! Check diary.
a year ago
4
5
Solved
TioRandy
Humidity in a small tentHow to preserve optimal humidity in a small tent? My target humidity is 70 as I am germinating. My tent is 60*60*160. The smallest vent is on the picture I have attached (310 m3/h, 180PA). I have a Xiaomi Humidifier running on the maximum 24h, but still no help
Setup. Ventilation
a year ago
12
9
Solved
GreenCosmos
(MarsHydro) Anyone have experience with this combo?I'm thinking about upgrading my ultra cheap duct fan and carbon filter to this beauty.
It has a thermostat controller and is under 250€.
It seems to good to be true for this price.
Is anyone using it and give me a review?
Setup. Ventilation
a year ago
8
6
