Need help with humidity (4x8 tent)

GrapeApe331

Member
So I have a 4 x 8 tent with (3) 1000 W full spectrum LED lights. I only have one oscillating fan going through it and my humidity has spiked to 76%! My plants are in their 1st week of flower so I have to resolve this ASAP! I live in MI and we been having a lot of rain. Would a 20 pint dehumidifier help or should I buy more fans?
 

NukaKola

Well-Known Member
So I have a 4 x 8 tent with (3) 1000 W full spectrum LED lights. I only have one oscillating fan going through it and my humidity has spiked to 76%! My plants are in their 1st week of flower so I have to resolve this ASAP! I live in MI and we been having a lot of rain. Would a 20 pint dehumidifier help or should I buy more fans?
Circulating fans aren't going to do anything.

If you are running CO2, then you need a dehumidifier. If you aren't using CO2 then you need intake & exhaust fans to bring in fresh air. If the air you bringing in is still high in humidity, then you will also need a dehumidifier.

The size of dehumidifier is dependent on how many gallons of water you feed per day.

What lights are you using? Most LED's that are marketed as 1000w are usually only 100-300 actual watts. Very few LED's are 1000W.
 

GrapeApe331

Member
Circulating fans aren't going to do anything.

If you are running CO2, then you need a dehumidifier. If you aren't using CO2 then you need intake & exhaust fans to bring in fresh air. If the air you bringing in is still high in humidity, then you will also need a dehumidifier.

The size of dehumidifier is dependent on how many gallons of water you feed per day.

What lights are you using? Most LED's that are marketed as 1000w are usually only 100-300 actual watts. Very few LED's are 1000W.
I’m using Philzon 1000watt so I’m not sure the exact wattage. But yes I’m using Co2 so the dehumidifier would be the proper requirement thanks for the help!
 

Romulanman

Well-Known Member
Have you taken a look at the vapor pressure deficit recommendations chart before? Generally the higher the RH the higher temps you need. 73-84 degrees would be ideal for about 76% in that growth phase.
 

NukaKola

Well-Known Member
I’m using Philzon 1000watt so I’m not sure the exact wattage. But yes I’m using Co2 so the dehumidifier would be the proper requirement thanks for the help!
30w per sq ft is the minimum recommended for flowering with LED's. Ideally you would want at least 960w of LED's in a 4x8. I would recommend adding at least another 600w. Only 300w is going to give poor yields out of a 4x8.
 

GrapeApe331

Member
Have you taken a look at the vapor pressure deficit recommendations chart before? Generally the higher the RH the higher temps you need. 73-84 degrees would be ideal for about 76% in that growth phase.
I did take a look at that and it would seem they are in the right range especially with my temps at 83 consistently. I’m running autos so lights is 24 hours so I thought the dehumidifier would come in handy.
Now I can say I have defoliate none since they grown. Should I do that as well?
 

GrapeApe331

Member
30w per sq ft is the minimum recommended for flowering with LED's. Ideally you would want at least 960w of LED's in a 4x8. I would recommend adding at least another 600w. Only 300w is going to give poor yields out of a 4x8.
Okay I will do that at a later time as I’m already in the midst of this grow already.
 

Romulanman

Well-Known Member
I did take a look at that and it would seem they are in the right range especially with my temps at 83 consistently. I’m running autos so lights is 24 hours so I thought the dehumidifier would come in handy.
Now I can say I have defoliate none since they grown. Should I do that as well?
If it keeps raining a lot in your area maybe start using a dehumidifier the further along you get. I would keep an eye on that if it keeps rising uncontrollably. Not sure how your plant looks so I can't say whether or not to defoliate but its a growers choice. Some plants I do more than others.
 

GrapeApe331

Member
If it keeps raining a lot in your area maybe start using a dehumidifier the further along you get. I would keep an eye on that if it keeps rising uncontrollably. Not sure how your plant looks so I can't say whether or not to defoliate but its a growers choice. Some plants I do more than others.
I’ll post a picture once I get back to them.
 

Romulanman

Well-Known Member
It's not too late to add more lights. 300w is only really adequate for flowering 10 sq ft.
This is true as well. For my 4x8 tent I have 1080 watts total with LEDs. Right about 33 watts per square foot. I have four 135 watts LEDs per 4x4 side.
 

HydroKid239

Well-Known Member
So I have a 4 x 8 tent with (3) 1000 W full spectrum LED lights. I only have one oscillating fan going through it and my humidity has spiked to 76%! My plants are in their 1st week of flower so I have to resolve this ASAP! I live in MI and we been having a lot of rain. Would a 20 pint dehumidifier help or should I buy more fans?
All I have is bro science.. defoliate everything 12 inches up from the pot.. it's "Supposed to help lower RH. Maybe research it.. I was trimming the bottom of the plant the entire grown and RH was never a problem.. but then again ur tent is like 3 of mine in one.
 

DrKiz

Well-Known Member
So I have a 4 x 8 tent with (3) 1000 W full spectrum LED lights. I only have one oscillating fan going through it and my humidity has spiked to 76%! My plants are in their 1st week of flower so I have to resolve this ASAP! I live in MI and we been having a lot of rain. Would a 20 pint dehumidifier help or should I buy more fans?
Get a 8” exhaust fan and vent outside.
 
Top