Under Current system, Sealed room, 6k lights, High Humidity problem

[horndog]

I am on my second run with this set up:

Completely seal room with Co2
6x 1000 lights
Under Current 28 site system (I took a 32 site system and removed 4 buckets)
mini split A/C system 30k btu's
two 24" air king fans
1 hp water chiller
IPonic environmental controller
165 gal reservoir to feed system
1 Quest Dual 205 Overhead Dehumidifier (removes 205 pt a day), out side the room
1 Dri-Eaz F413 Revolution LGR Dehumidifier (removes 81 pt a day), inside the room

MY problem is the HUMIDITY is still way out of control. I can not get the humidity below 60% during the bloom cycle. Is anyone else having the fight of their life with the humidity and running this system. My first grow 4 plants did not make it and I still pulled 12 1/2 pounds with the remanding 24 plants.

1) do you have a high humidity issues with this system?
2) how are you dealing with it?

 

[ttystikk]

1. Yes, only much more than you are

2. Rather than consider it a 'problem'. I read up on VPD, or vapor pressure differential. Our plants like their RH in the high sixties and seventies during bloom. I have consistently great crops to prove it.

 

[jijiandfarmgang]

Humidity is relative

To really know whats going on you should monitor your humidity every hour for a 24 hour period. Or at least a few hours after lights out and before lights on, and a couple intervals lights on.

Perhaps your temps are dropping a lot during lights out causing a spike.

Not saying this is your issue, but something to look at.

- Jiji

 

[horndog]

ttystikk
Thank you for your response friend , if you own a set up like ours your better know something about VPD=Vapor Pressure Deficit . I don't see any evidence of VPD burning on leaves and condensation is at a minimum. I have a tight control on day vs night temps I believe.

jiji
I am not seeing any adverse effects actually in my grow, my problem maybe just be with the info and expectations that Current Culture puts out in their feed schedule that the humidity should continue to drop down to a 40% by day and 20% by night range during week 8. If anyone is able to get that low how are they accomplishing that feat.

By the way Jiji, I have a lot of respect for you. I have seen you prove many fools wrong on these boards with sound theory and practice. Thanks for chiming in here.

I guess guys I would ask, is high humidity an issue then? I still feel somehow my crop might turn out better if I could end with lower numbers.

 

[ttystikk]

ttystikk
Thank you for your response friend , if you own a set up like ours your better know something about VPD=Vapor Pressure Deficit . I don't see any evidence of VPD burning on leaves and condensation is at a minimum. I have a tight control on day vs night temps I believe.

jiji
I am not seeing any adverse effects actually in my grow, my problem maybe just be with the info and expectations that Current Culture puts out in their feed schedule that the humidity should continue to drop down to a 40% by day and 20% by night range during week 8. If anyone is able to get that low how are they accomplishing that feat.

By the way Jiji, I have a lot of respect for you. I have seen you prove many fools wrong on these boards with sound theory and practice. Thanks for chiming in here.

I guess guys I would ask, is high humidity an issue then? I still feel somehow my crop might turn out better if I could end with lower numbers.

VPD theory says that plants do better with higher humidity at the temperature we run indoors;

'Keep it in the green'

This chart says that the ideal RH for plants in the mid 80s is 80%! I run mine in the seventies and they love it:


Keep your nighttime and daytime RH as similar as possible; it's the wild swings up and down that promote pathogens.

 

[jijiandfarmgang]

First 20 percent humidity thing sounds crazy.

I was going to make a big post, but generally I look at it pretty simply.

I keep it usually under 70% in veg , and under 50% in late flower.

Everyones different. And so are the strains they run. I'm always trying something new, and like to keep things simple and consistent. I like to play on the safe side.

I've found if I get closer to 80 percent indoors, even with good airflow, I run into moisture problems, such as wet corners or wet somewhere with drywall etc. I suppose its how your room is constructed.

- Jiji

P.S. thanks for the compliments

 

[horndog]

ttystikk
That wall of green is beautiful, g-damn son....beautiful.
Thanks to you I am going to tighten my day and night temps even more, thanks friend.

 

[horndog]

jiji
Yes 20% does sound unreal I total agree, but I would like to bring it down to 50% towards the end thats my sweet spot. What kind of equipment are you and everyone else using to achieve that. I have a total of almost $5000 invested in those two dehumidifiers listed just for that one room, and I have two duplicate rooms for a total of $10k in just humidifiers alone and they struggle. The Quest 205's are F'en awsome but still struggle.

 

[GIJonas]

With strains that don't mold - high humidity seems to rock. Have critical kush lady's at 80° and 80% and they love it. For some reason I observe denser growth than when the air is dry.

 

[jijiandfarmgang]

jiji
Yes 20% does sound unreal I total agree, but I would like to bring it down to 50% towards the end thats my sweet spot. What kind of equipment are you and everyone else using to achieve that. I have a total of almost $5000 invested in those two dehumidifiers listed just for that one room, and I have two duplicate rooms for a total of $10k in just humidifiers alone and they struggle. The Quest 205's are F'en awsome but still struggle.

I have a lgr 270htx...... don't really use it though, I might have to use it once this year.

Basically I have a kind of unique setup. Works for my climate, but it also has its own pitfalls. My rooms aren't sealed. I live in a cold climate, and its cold for about 9 months of the year so its usually dry. I have a 2000 cfm vortex exhaust fan thats connected to my homes ductwork. I generally use 1 cheap supentown 70 pint dehumidifier for lights off in the warmer months. I also have a 24k minisplit for warmer months, nothing needed in winter.

- Jiji