Question about humidity during night cycle

I have a 8.6 by 4.3 by 7 foot tall grow tent and i am having problems with humidity in the room at night. going from 50-60% when lights on(21ish degrees Celsius ) to 90% when lights are off (15ish degrees Celsius). Will this change affect my plants or is it normal to have 80-90% humidity during the dark period in these temps? Or do i need to run a dehumidifier at night?

Sounds like a ventilation issue.

How is your ventilation setup?

What ventilation equipment do you have?


J

I have a 6 inch inline and a 4inch (6inch)for carbon filter (4inch) for cooling1 1000w hps and 1 600 watt hps both are off at night because there is no smell yet. SHould i keep the smaller one on at night every 15min out of every hour or run my larger one?

Hmm all I know is that's way to much humidity for any cycle ur gonna have mold/fungus issues if not corrected

I am a lil confused with the description of your setup but whether it smells yet or not u should run the fan connected to the filter all the time/constantly unless your running co2 without a sealed room. That will probably solve your humidity problem and u should always b recirculating the air in the room as much as possible your ladies love fresh air. Hope that helps. Let me know

lets put this into perspective.

I use 1x600w HPS aircooled using a 6inch 400CFM / 660m3h RVK150L1 this is a sealed aircooled system where no grow room air passes through the lighting. Then i have a 5inch 160CFM / 260m3h RVK125A1 with a 200CFM / 350m3h carbon filter that creates my air exchange/scrubbing . My 5inch runs 24/0 to always scrub my air. The 6inch runs when the lights are on and is speed controlled.

4inch for cooling?? Do you mean an INTAKE?
6inch for scrubbing .

My guess is that your fans arent powerful enough to effectively remove the humidity. Carbon filters struggle to work above 80% RH.



J

Add a dehumidifier. Problem solved. Get a big ass one.

Does yourfilter Exaust air out of the room or recirculate within the room your light set up with Exaust sounds nice but u need to change the air in the room around once every 3 min if u r doing that humidity shouldn't b a problem

Ok so i changed the timer so filter is on all the time. It is inside the tent and the 6inch fan is pulling out of the room and outside. humidity is in the high 60s. O yea while trying to change timer I knocked over the carbon filter that was on a unstable table. Needless to say it landed right on one of my kings kush plants!!!!!!!!!!!!!!!!! This plant was 3 feet tall and about the same across. I have been L.S.Ti it and It had about 30 bud sites on it. The damn filter cut a quarter of the plant off!!! needless to say pretty mad at my self but i think that the plant broke the fall and saved the filter. Is it bad if the filter fell and hit its side? No damage to the filter that i can see.