Long time shmoker 1st time grower. Just flipped my 2 Amnesia Fast girls to flower. Been going well so far. In S california so generally high humidity not an issue (although moving to midwest in 5 months so this thread will help more when I move). Of course the week I wanted to start flower (end Dec.) we hit several days in a row of rainy weather with high humidty. Bought a mini dehumidifier (eva-dry 1100) plopped it in tent right in front of intake and maybe got the rh to drop 2% over 2 days of trial. All week I’m @ 60% RH w lights on (avg temp 78F) & 70% RH lights off (avg temp 67F). Tent seems to stay @ 10% higher RH then house RH. Mars hydro tsl2000 light, 4" inline fan exhausting into attic, passive air intake 6" secret Jardin light baffle insert. clip fan circulating air low w small osscalating fan blowing across tops of ladies. Coco/perlite “tupar” medium in 3gallon fab pots, was doing twice a day high water fertigation watering method but cut that back to once a day to see if that helps RH at all (always watering to runoff & removing saucer water daily) Thanx in advance for any advice
Hy @JimmyDuxFan and welcomed to the community if all you plants are in flowering stage I deal with my hr without humidifier just opening my tent
For example if I closed my tent the hr go from 60% to 85%
And opening my tent the hr go from 55% until 40% sometimes little low but all time be in 45%
Actually you’re sitting pretty for daytime temp and humidity. The night time temp and humidity are an issue though. At 67° you want to be around 40-50%. Any way of getting a larger humidifier or maybe a heat source to bring the temps up?
welcome to the community and the humidity. These pros will help you.
Is your 4” fan causing negative pressure (sucking in the sides of the tent)?
My tent is in corner of my large master bedroom so I would’t be able to open tent during “lights out” because the rooms being used (main reason I added the Light baffle air intake and sealed up the tents vents)> a small heater could be an option but space is tight in the 2’x4’, I might have to try putting a heater right next to air intake on outside of tent. Gonna return this $40 dehumidifier and look at small space heaters. My RH #'s will prolly be fine most of flowering time as this higher humidity is rare in Ca in winter but I’m kind of a perfectionist and want to make it close to perfect I can. In midwest I know I’ll deal w this situation more often but I’ll be in a basement then and prolly will do large couple hundred $ room dehumidifer then.
As for neg pressure yes some sucking in when I crank inline all the way up. The light baffle does restrict air flow alittle more the just having 1 the bottom tent flaps open but there is a definite difference in temps and rh by adjusting inline fan speed up and down. Was running it maybe half speed through veg as temps aren’t a prob w led’s but have cranked it to max when Rh grew this week and thats when I could see some neg pressure wall sucking in.
@JimmyDuxFan
My tent is a 2x2x4 to but I had my tent in the living room open like this
Went hr is to low I jut cover with tower and hr get up like 10% or 20% up
50% is good to run until harvest just look you plants, you should be good high hr make mold on you plants
I added a small space heater outside the tent next to the intake and lights out I’m now keeping it @ 76F and the rh has been @ 60%avg lights out now. Gotten it down to 48-49% rh couple lights out even. Humidty has been all over the place in S Ca. last 3 weeks. Pay attention and adjust I guess lol
I know this is from several years ago, but this is happening with my small tent. I also happen to be struggling a bit to get my rh down for flowering.
Is this a sign that not enough air is getting taken in through vents?
Spaceface.
I have a very small tent in flower also. Some things that have worked for me are pulling the air in from the floor of the lung room and heating that same air to drop the humidity of the tent.
Lot of growers do not realize the speed of water a flowering plant will release. As such proper through put of outside air to remove this is important. Also is properly humidity of that air
Here is my current numbers
You will notice that the room humidity is much lower than my tent. Seems like pumping that dry air in should lower it.
Yes it does, at duct level 7. Any lower setting and the humidity goes up. The plant is spewing so much water I have to exchange the air in a constant stream to control it even with 25 points lower humidity than outside.
That’s why the duct speed goes from hum to howl. You may need it.
Thanks for the reply. I’m in the same situation with the lung room being significantly lower in rh.
I’ve got a clip on circulation fan going, plus the fans built into the lights (what’s shown on VIVOSUN hub), and the inline full tilt. I’ve since learned, but I think it’s gonna be a struggle for me bc I’ve got 2 - 5 gal fabric pots in my 3x3. It’s just too much of a baseline humidity to begin with, imo.
I’m gonna swap out my 4in intake duct with 6in and see if that helps my cause. Perhaps another small circulating fan on the floor.
Next grow I’m just gonna do a single plant and scrog out the canopy to the footprint of the tent. Thankful for this forum it’s such great resource.
I love the Vivosun with the fan in the lights. I am running 2 150 watt units in a 31x31c63 tent so heat has not been an issue.
Looks like you need another 20% reduction in your lung room.
If you have an extra humidity sensor put it on the floor and check floor level. I moved my sensor choice from the built in Vivosun to the remote sensor and put it on the floor next to the intake for the heater box and the fresh air. That is why mine reads so low. Using the built in that mounts to the tent about 4 feet up it reads 42%
In addition one more tip. Removing humidity is easier in a small tent. If you have your light lowered down to your plants on the floor consider moving the light up and moving your floor up as well. I have a 12 inch dead space that reduces the cubic feet of the tent by 6.7 cubic feet making the air exchange faster. I fabricated a panel and placed it on 4 3 gallon buckets. Not that you should do that right now but you could try it next grow.
I actually hard mount my lights to the top of the tent so I can level them out. Then move the plants down as the grow progresses.
If you have good air movement, that humidity is not that bad. That’s a good harvest drying humidity. You could also be getting a reading from an area in the tent that is reading higher than other areas. I’m not familiar with that app nor the sensors it utilizes.
I’ve got airflow like crazy. Fan below near the 6in duct intake, circulating fan above canopy and the fans in the lights.
My tent is in my garage which is insulated very similar to another room outside of the garage door. I’m not sure what else I can do. The temps and rh in garage aren’t bad but I can’t get it to equalize.
Should I be worried and trying to resolve?
I grow for my own use and we’re talking about a two plants. With that being said, I’d like best quality I can produce, but I’ve got limitations.
I’ve got multiple hydrometers in the tent and everything is +/- a few %
@BobbyDigital thought I replied to your message but it appears I didn’t. See above
Could you maybe put a dehumidifier in your lung room? Bring humidity down and temp up in one shot…
Moving air is often easier when Exhaust Fan is at top of tent and intake can be bottom of tent or static.
Moving air out of the tent may influence RH.
That’s my current setup. Inline exhaust at the top. 4in that came in the tent kit. I added a static fan near the intake at bottom on tent floor to increase airflow.there really isn’t any direct air on leaves but they’re moving somewhat from all the circulating air. At this point, outside of dehumidifying the garage, I don’t think I can get the RH any lower inside the tent. Just hoping the airflow is enough…
