Problem with humidity control in tent

[rocks911]

I have a 2x4x5 tent with a few White Widow girls and they are in the first weeks of flowering. I have a AC Infinity Cloudline T6 in the tent with a Vivosun filter. I also have a portable A/C unit outside the tent that feeds cold air into the tent through a flexible hose.

My problem is that I cannot do without the A/C unit as it is hot in my garage where I have the tent and really with the use of the A/C unit the temp is perfectly stable at around 71 degrees F. Unfortunately the Cloudline T6 is ineffective at bringing down that humidity level. I ran the T6 at full speed for three hours and the humidity level wasnt effected at all. Which makes me think that the A/C unit is delivering 70%+ humidified air. I also have one of the fresh air port open at the bottom of the tent drawing air from the garage. I havent really analyzed air flow and maybe I need more ambient air from the garage? Maybe?

What I know is I gotta have the A/C, and I gotta bring the humidity down.

Ideas?

 

[Oldbear]

What’s the rh in the garage?

 

[rocks911]

48% rh in the garage. 68% in the tent with the A/C running and T6 running slowly at speed 3 which is 150 CFM

 

[No Pain]

48% rh in the garage. 68% in the tent with the A/C running and T6 running slowly at speed 3 which is 150 CFM

Okay well depending on what stage in the grow you are at 68% humidity is nothing to worry about look up VPD its golden information for a grower . 71 degrees in the tent seems awful cold to me . So like I stated look up VPD get yourself a handheld laser thermometer and check the leaf surface temps as they are not equal to ambient air temp especially with a t6 .

 

[Oldbear]

Something to try, might be to disconnect the outside tent ac from the tent and just pull in garage air with the lower rh.

 

[rocks911]

Okay well depending on what stage in the grow you are at 68% humidity is nothing to worry about look up VPD its golden information for a grower . 71 degrees in the tent seems awful cold to me . So like I stated look up VPD get yourself a handheld laser thermometer and check the leaf surface temps as they are not equal to ambient air temp especially with a t6 .

Thanks for the VPD info it has proven helpful if frustrating. Also, Ill be getting a laser thermometer, thanks for that.
My problem is that my tent sits in a garage in Texas. This time of year temps in the garage run in the upper 90's F during the day and settle to the 80's at night.
Judging from the VPD chart it is obvious that marijuana plants like it hot and dry. But I cant hit the target temp/RH in any consistent manner.
Unfortunately my portable A/C unit has no adjusting, it just blows cold air. My thought was to error on the side of cold to produce tighter buds.

I have to wonder about my strategy. The plants look great but that might be just because of genetics and they're doing great despite my inept attempts at managing climate control. So if one had to choose the right environment for in-tent soil grown White Widow plants 3 weeks into flowering would one opt for trying to manage them at 90 F or 70 F?
The VPD chart seems to indicate that 90 F at 72 RH is right in the sweet spot and that is doable for me, at least for some part of the day. But I thought humidity was supposed to be low, low, low and 72 RH is not low.

This morning with the A/C running its (according to the Cloudline T6 probe near the top of the tent) 73 F and 69 RH which is way out of the preferred VPD sweet spot. Im gonna turn off the A/C and see what happens.
What freaks me out is that there is no possibility to bring the temp down to where it is lethally cold but I could easily not manage the temp correctly and have these lovely plants fry.

What high temp would kill this grow?

 

[Sask420grow]

Use fans. Lots of fans. It will move the air and the buds so you don’t get bud rot. That’s what your concern is right? 70% in flower is a little high. 71f is perfect for flowering. The humidity can be lowered if you put the ac in the tent. Use the ac to pull the humid air out. Check out the grow boss YouTube video on how to keep things in check.

 

[rocks911]

Thanks for the reply. Yeah I kinda grew a jungle which was easy to manage till the heat hit. Dont have room in the tent to move the A/C in.
Im just gonna run hot and only run the A/C at the absolute hottest few hours, if at all.

Mostly I heave to get a balls accurate reading of temp and RH in the tent at plant level. What I have now is the T6 probe telling me what the temp is at the ceiling and a hygrometer/thermometer sitting on the floor of the tent. They are typically 10 degrees apart. But during lights out I have less of a clue exactly what the temp is.

Can anybody recommend an accurate hygrometer/thermometer that has Blutooth or another mechanism to keep me aware of temps during lights out? And where to monitor, at the canopy level?

 

[No Pain]

Thanks for the VPD info it has proven helpful if frustrating. Also, Ill be getting a laser thermometer, thanks for that.
My problem is that my tent sits in a garage in Texas. This time of year temps in the garage run in the upper 90's F during the day and settle to the 80's at night.
Judging from the VPD chart it is obvious that marijuana plants like it hot and dry. But I cant hit the target temp/RH in any consistent manner.
Unfortunately my portable A/C unit has no adjusting, it just blows cold air. My thought was to error on the side of cold to produce tighter buds.

I have to wonder about my strategy. The plants look great but that might be just because of genetics and they're doing great despite my inept attempts at managing climate control. So if one had to choose the right environment for in-tent soil grown White Widow plants 3 weeks into flowering would one opt for trying to manage them at 90 F or 70 F?
The VPD chart seems to indicate that 90 F at 72 RH is right in the sweet spot and that is doable for me, at least for some part of the day. But I thought humidity was supposed to be low, low, low and 72 RH is not low.

This morning with the A/C running its (according to the Cloudline T6 probe near the top of the tent) 73 F and 69 RH which is way out of the preferred VPD sweet spot. Im gonna turn off the A/C and see what happens.
What freaks me out is that there is no possibility to bring the temp down to where it is lethally cold but I could easily not manage the temp correctly and have these lovely plants fry.

What high temp would kill this grow?

You're welcome . Now here is the thing about VPD that is important for all growers to understand that are just starting to us it . Is its about the plants transpiration ….back in the day when people where saying you need to have the humidity at 45RH during flower they weren't concerned about the plants transpiration they where doing that because of things like bud rot and felt that it had to do with humidity mostly ...and what causes that is drastic difference between day and night temps along with humidity...there are different parts of the chart to look at for temps and humidity levels one is veg , then you have early flower and late flower . There is also a chart out there the accounts for leaf surface temp made by Everest Hernandez and that is the one I would recommend following .

No in regards to being able to control that the best you can in your situation ...your tent is in a garage so you have to choices that would be best ...one would be to build an enclosure and insulate your tent/grow space from the environment it is in … 2nd would be to control the environment in the garage the best you can ...meaning run the a/c in the garage and bring down the temp and run the dehumidifier in the garage to control the humidity % .I say that because a tent is paper thin and aside from the light being on will have the same temp as the room surrounding it and that is te area that you are pulling fresh air in from .

anyways hope this helps

 

[rocks911]

Thanks, very insightful. Ive got a thermal gun coming
Unfortunately the probe/controller on the AC Infinity is wildly off on humidity levels. I had to spend some time and really pay attention to what was going on and I finally came to the conclusion that Im entirely at the mercy of the climate. What was I thinking! of course the RH inside the tent isnt wildly different from the garage! I should have suspected the probe early in this process.

I had a different idea about what the AC Infinity T6 would do for me. I thought it was about temperature and humidity control, which it is to within a couple points of either temp or RH but not nearly as big a difference as I had hoped. My thought is that the Infinity T6 and every other air mover out there is really about air exchange keeping down the smell and maybe helping keep fungus/spores from finding a home by keeping the air moving. Is that right? I see very little difference in temp or RH in the tent no matter how fast or slow its running.

 

[No Pain]

Thanks, very insightful. Ive got a thermal gun coming
Unfortunately the probe/controller on the AC Infinity is wildly off on humidity levels. I had to spend some time and really pay attention to what was going on and I finally came to the conclusion that Im entirely at the mercy of the climate. What was I thinking! of course the RH inside the tent isnt wildly different from the garage! I should have suspected the probe early in this process.

I had a different idea about what the AC Infinity T6 would do for me. I thought it was about temperature and humidity control, which it is to within a couple points of either temp or RH but not nearly as big a difference as I had hoped. My thought is that the Infinity T6 and every other air mover out there is really about air exchange keeping down the smell and maybe helping keep fungus/spores from finding a home by keeping the air moving. Is that right? I see very little difference in temp or RH in the tent no matter how fast or slow its running.

You are welcome. good to hear you have a thermal gun on the way . In regards to rh being different in the tent from the garage it will be because of plant transpiration more so at lights out than during lights on . Yes they are for air exchange and keeping airflow moving and for odor control when connected to a filter and the length of ductwork cuts down on its efficiency .
The more airflow you have being exchanged the more you are subject to the outside air temp and rh causing change inside your tent . That is why in your case it would be best to control the temp and rh in the garage , so that it will have a more positive effect on what's going on in the tent.