4x4x6 dehumidifer

I hope everyone has had a happy growing finish to the year and good growing in 2020

I have a 4x4x6 grow tent, 2 5 gal pots with 2 week 9 vegging females, I have humidity holding between 40-60% on high and lows of watering cycle. The 70 pint dehumidifier is holding it from outside the tent (set to 35% in small grow room with tent inside).

The Issue is this, there are only 2 plants in veg and the humidity will need to drop to 30-40 rh% for flowering but the 70 pint dehumidifer outside the tent wont be able to consistently keep the RH at 40% or below.

Solution:
I have a 30 pint dehumidifier that can go into the tent. I wanted to return it because I got the 70 for free from family, but it seems like its necessary.

Problem 2:
Its pretty large for a 4x4x6 tent and I wanted to SCROG

Solution 2 (options):
1) abandon the SCROG and just LST as I have been doing (haven't been able to lower the scrog due to broken foot and too much trouble), and basically just grow bushy plants which is ideal for height restrictions and greater yields.
2) Raise the plants 6" up (lets say a DIY solution like milk crates under the planters, the screen goes just above the dehumidifier.
3) Just get a small 2000ml or less shitty dehumidifier from amazon (will this be enough to drop the Rh below 40 on its own or will it need to be working with the 70 pint outside the tent simultaniously?)
4) go off the board for a better solution I don't have

Potential problem 3:
Heat given off by the dehumidifer inside the tent, may become problematic but white widow seeds love heat apparently (but in the summer, potentially...not really worried about this now)

- Tent Climate Range: (Ac infinity 6" fans on 10, 2 6" mini fans on high, all inside a 10x12x7 side room)
40% needs water
60% just watered
66 night time temp
73-77F expected normal lights on temp
81F max recorded temp

Sorry for the long winded post, First grow and trying to get it all sewed up here.
 

SheeshM

Well-Known Member
I have a 70 pint DH outside my tent and I just tie a 4" flex duct to the DH output grill and pipe it into my tent using a low port. So the DH is keeping the room rh decent but also injecting really dry air directly into the tent. As you mentioned, DH produces heat which you are now sending to your tent. I pipe cool air from a portable AC into another tent port to fight the heat. Not the most efficient system, but it works and my space is in an attic with poor insulation. I also use the Bluebird rh and temp controllers to automate the temp and rh in the tent.
 
I have a 70 pint DH outside my tent and I just tie a 4" flex duct to the DH output grill and pipe it into my tent using a low port. So the DH is keeping the room rh decent but also injecting really dry air directly into the tent. As you mentioned, DH produces heat which you are now sending to your tent. I pipe cool air from a portable AC into another tent port to fight the heat. Not the most efficient system, but it works and my space is in an attic with poor insulation. I also use the Bluebird rh and temp controllers to automate the temp and rh in the tent.
The AC Infinity inline fans, and both dehumidifiers have auto programs to stay at the relative set rH and or temp but I like the ink birds and tried it out but just wasn't needed. I don't think heat will be much of an issue as the White Widow strain is said to thrive in higher temps, even upwards in the 80's.
Summer may call for added cooling measures, but I also have the option of ducting out a window directly. This would solve the problem easily, and all other problems discussed but would also just move the costs to house heating/cooling as the cfm on the exhaust out the window creates a pull inside the chimney upstairs.
This option is there as a last resort if the carbon filter and tent fail to hold the smell inside significantly.

Could you simplify or show me more specifically what you are talking about because thats something I was looking into also. Specifically referring to the dehumidifier--> ducting-->inline fan---> ducting --> tent or whatever chain you are explaining. sorry first grow so a little slow here.

I currently have a carbon filter there, but its just added insurance. So I basically have a brutally inefficient system of what you are saying
 

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Just curious why you want your humidity so low?
Basement grow, history of mold in basement, heard it was ideal to avoid mold issues. I am not worried or expecting mold but I rather spend a little more up front and guarantee never losing a crop to it. Probably going overboard and concerned but here we are.
 

SheeshM

Well-Known Member
The AC Infinity inline fans, and both dehumidifiers have auto programs to stay at the relative set rH and or temp but I like the ink birds and tried it out but just wasn't needed. I don't think heat will be much of an issue as the White Widow strain is said to thrive in higher temps, even upwards in the 80's.
Summer may call for added cooling measures, but I also have the option of ducting out a window directly. This would solve the problem easily, and all other problems discussed but would also just move the costs to house heating/cooling as the cfm on the exhaust out the window creates a pull inside the chimney upstairs.
This option is there as a last resort if the carbon filter and tent fail to hold the smell inside significantly.

Could you simplify or show me more specifically what you are talking about because thats something I was looking into also. Specifically referring to the dehumidifier--> ducting-->inline fan---> ducting --> tent or whatever chain you are explaining. sorry first grow so a little slow here.

I currently have a carbon filter there, but its just added insurance. So I basically have a brutally inefficient system of what you are saying
I just catch some of the dehumidified air and pipe it into the tent. The DH keeps the air in the room at a decent rh but the small hose going directly into the tent quickly removes rh spikes, especially after feeding/watering. I've posted a photo but ignore the nylon stocking on the hose. I thought I would screen the ducting but it constricted the airflow too much.
DH.JPG
 
I just catch some of the dehumidified air and pipe it into the tent. The DH keeps the air in the room at a decent rh but the small hose going directly into the tent quickly removes rh spikes, especially after feeding/watering. I've posted a photo but ignore the nylon stocking on the hose. I thought I would screen the ducting but it constricted the airflow too much.
View attachment 4447326
thanks!
 
I ended up putting the 30 pint dehumidifier in the tent, closed off the room vent to stop new warmed air from coming into the room, and then opened the door. Temp now in the 80's and humidity is whatever I want it to be :)

Thank you to all the contributors

I kept the SCROG but added milk crates to kick up the height of the plants by 11", now it makes watering and maintenance 10x better, better airflow, and it makes the bulky dehumidifier half the height it used to be :)
 

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JavaCo

Well-Known Member
This is my planned RH for flowering, do you think that is too much?
  • 55% week 1
  • 50% week 2
  • 45% week 3
  • 40% week 4
  • 35% week 5
  • 35% week 6
  • 30-35% week 7
  • 30-35% week 8
  • 30-35% week 9
You might want to check out VPD vapor pressure deficit. Basically tells you what humidity is best by factoring in the difference between room temperature and leaf temperature of the plants. Here is a article on it https://www.cannabissciencetech.com/growers-and-growing/understanding-vpd-and-transpiration-rates-cannabis-cultivation-operations
 

ChrispyCritter

Well-Known Member
You did what I would have done so I hope it works lol. Option 3 would never have worked. Those little dehueys don't work at all for tents. Small spaces are a challenge in so many ways. Im not convinced scrog yields that much more than lst compared to the grower effort involved and im not big on defoliating for a scrog but I'm talking out my butt. Good luck with everything.
 
You did what I would have done so I hope it works lol. Option 3 would never have worked. Those little dehueys don't work at all for tents. Small spaces are a challenge in so many ways. Im not convinced scrog yields that much more than lst compared to the grower effort involved and im not big on defoliating for a scrog but I'm talking out my butt. Good luck with everything.
Thanks buddy, thats what I am gathering myself, LST was easy because it was more flexible, the SCROG is easier in many ways but with the awkwardness of it all its going to be a tough call. As far as the defoliation goes, it has, to me not caused any problems and the plants do not suffer at all from it
 

madvillian420

Well-Known Member
You did what I would have done so I hope it works lol. Option 3 would never have worked. Those little dehueys don't work at all for tents. Small spaces are a challenge in so many ways. Im not convinced scrog yields that much more than lst compared to the grower effort involved and im not big on defoliating for a scrog but I'm talking out my butt. Good luck with everything.
No need to choose just one, i do 3 weeks LST, add my screen, another 2-3 weeks veg, then 12/12. the screen absolutely helped me, and is an excellent anchor point for more branch tying/manipulation. I havent done much defoliation either, definitely not the whole "strip everything below the screen" method. Im not much for doing things "by the book" or the exact way people agree and assume is the best
 
No need to choose just one, i do 3 weeks LST, add my screen, another 2-3 weeks veg, then 12/12. the screen absolutely helped me, and is an excellent anchor point for more branch tying/manipulation. I havent done much defoliation either, definitely not the whole "strip everything below the screen" method. Im not much for doing things "by the book" or the exact way people agree and assume is the best
Yea I did LST from week 4-8 then put the SCROG on, I wouldnt have waited but my ankle was in a cast. Next grow ill add more plants so I can veg less
 

Growhobby1975

New Member
Hi, totally off topic, so I apologize, but I have been searching high and low for a 4x4x6 tent due to limited headspace in my basement, and there are very few out there. I was wondering if you could tell me the brand of your 4x4x6? Thanks
 
Hi, totally off topic, so I apologize, but I have been searching high and low for a 4x4x6 tent due to limited headspace in my basement, and there are very few out there. I was wondering if you could tell me the brand of your 4x4x6? Thanks
Hey,

Check out the mammoth p120 it’s 120x120x200 cm or basically 3.9x3.9x5.9. it’s a really good tent for the price and very little complaints. (Maybe just the lack of ports and vents, and light leaks in the zipper basically)

Here what you need to know also. The venting comes out of the roof. Meaning you need basically another 6 inches comfortably. I vent it with a 6 inch ducting so once than bends it adds another 6” so you’d need comfortably 85 inches of head space really. Solid tent and good price! Otherwise just bite the bullet and get the gorilla tent shorty. Double the price but a 5x5. Far superior tent but not much of that superiority makes a difference to be honest.
 
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