I grow in a 4x4 tent, located in my basement. The lung room is a walled off 140 square foot section of the basement, and the basement overall is about 900 square feet. Humidity in the lung room/basement appears to hover between 50-55%. Humidity in the tent appears to hover between 60-65%. I can’t seem to get humidity below 60% in the tent (not surprising if the lung room is 55%).
I tried exhausting into a separate room within the basement, and got a small 6 pint dehumidifier to sit in the small lung room. Neither appear to have impacted anything.
I’ve got some plants in about week 2 of flowering. I’ve read that 60% humidity is on the higher end of what’s “safe” at this stage of flowering, but you’d want to get it down to 40% or below in later flowering.
The only way I know to drop the humidity more is to get a larger, 100 pint dehumidifier. I’d prefer not to do this, as it not only increases cost, noise, and heat, but larger dehumidifiers are notorious electricity hogs.
Do I need to be concerned, or is 60% humidity throughout flowering fine?
The weather at my place took a sudden turn for the worse. From 30% rh to 80% in just 2 days, thanks to a cyclone. The plants are still doing great. I’m approaching week 5 of flower.
I think you’ll be fine. Make sure you have a fan running. Plenty of fresh air exchange is key.
If you have enough airflow 60% should not be a problem, but you have to check if lights are turned off how high the humidity will rise. Usually after flower week 5-6 you want the humidity to be more on the 45-55 % range. A dehumidifier with about 150-200w power should do the work. And check your VPD for better accuracy.
I’ve got some trouble here in the last weeks of flower… The buds were too dense, so in the space between the stem and the bud that touches the stem, I’ve got some mold… Take care of the larger and dense top buds… Because if it’s 60% in the tent, probably in this area u will get a lot more than 60%… Thanks to the correct ventilation and exhaust, the mold doesn’t propagate to the external side of the buds… And in the same moment that I saw that I’ve got to do more than 1 week of flush. But prefer to harvest at the exact same moment.
My exhaust fan is typically moving about 240 cfm (not counting restrictions) which would be a full exchange about once every 30 seconds. If I set a dehumidifier in the tent, by the time it pulled humidity out of the air, the 55% humidity coming into the tent would swamp it.
It can be trouble if some biotic and abiotic factors are against what u desire… Like… If u have the cultivar that is mold tolerant… Like @CocoaCoir says… Tropical plants normally will show this characteristics… If u get some good exhaust and ventilation… In the 2 weeks of flowering, it probably will not grow mold… But in the 6~9 weeks in the stem-buds part can get mold… Because of the compactness and density of the buds…
Dehumidifier’s are not created equal… Get a dehumidifier that was designed for gardening. They can remove a lot more moisture from the air at a much larger spread in temps. I would suggest a Quest if you can spend some cash. Running into the 60s RH late flower is risky. If you want to run in those conditions a proper dehu will make it a lot better environment for your garden… Cheers !!!
If you don’t want to spend on a better dehumidifier or make holes to exhaust outside and/or bring in fresh less humid air from the house, just let it ride. What else is there to do? Maybe you get mold, maybe you don’t. I’d get out of the tent if controlling humidity is an issue and have the air moving as much as possible without hurting plants.
