I have recently flipped to flower giving my two ladys 36 hours of darkness and switching to a 12-12 cycle.
however when the lights are off i need to close all flaps on the 2.3-2.3 mars hydro tent to ensure there are no light leaks.
But with the two 4" fans on and my carbon filter also on( Filter on inside and fan on the outside) i am experiencing negative air pressure ( the sides of the tent are bowing in! )
I have run some more 4" ducting from a seperate hole and meshed it so airflow is not as extream and to get outside air into the tent but the sides of the tent still bow in.
So my question is simply,
does negative air pressure effect the plants or do i have nothing to worry about
Thanks guys
Kind regards
LG
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It may be ok. What size grow tent? 2.3m x 2.3m? Maybe use a 6" duct out of the bottom ventilation sock (instead of 4") and angle it so light doesn't leak in?
Yes chris the tent is 27inchx27inch x63inch running a gdf100-p, 322 airflow and speed is 2350rpm.
I have angled the ducting and have no light leak issues as i put a sports sock over it to stop any crap getting in there.
Mwhite pointed out that a fan speed regulatior will remedy this issue so i have ordered one with a probe. Here is the link incase anyone else has the problem of an inline fan that has no speed setting https://www.amazon.co.uk/dp/B089DQSB5F/ref=cm_sw_r_cp_apa_fabc_ft8QFbH2XG0WT?_encoding=UTF8&psc=1
A little negative pressure isn't bad in my opinion. I don't grow in tents anymore but I do dry in them. I have a fan in and one out on dimmer switches I adjusted to balance tent pressure. I don't suggest doing that unless you fully understand electricity. You can get fans with speed adjustment and add one for the inlet, slowly adjust up until walls have a little shake without sucking in or ballooning out. Now I've seen people open vents and put dark towels over them but not sure if that keeps the light out.
Thanks for the reply mwhite 👍 ill shop about for a fan with speed adjustment sounds like it will do the job nicely