High humidity when lights off 12/12 how to lower ?

C

Cocogrow1234

Member
during the day when lights on 12/12 my temps and humidity are perfect at 70-80f & 45-60% . When lights go out the temps lower to 60-70f and humidity rises to 70-80% .

tent : 1meter width x 0.5mtr depth x 1.8meter height so only a small space , the tent is in a small room about 2x4mtrs
6” extractor fan with carbon filter
I Don’t have a intake fan but have the vents open on the tent. (Passive intake )
lights : 2x mars hydro ts1000
I have 4 plants in total : 2 in 11l pots ,1 in 20l pot and 1 in 3l pot and there on day 1 of 12/12

i have a humidifier but it has bright blue lights on it so cannot use it in the tent when lights go out .Is there and small cheap humidifiers that doesn’t have a bright light on it ?

I have put a dehumidifier pot and bag in the tent but only done that today so no sure how effective they will be and over time the cost of these will add up so not sure this is the answer ?

I have read raising the temp by adding a heater will lower the humidity, this could be a idea as I can turn the heating on in the room the tents in , and the hot pipes are actually below the tent so kind of heats the floor below the tent when heatings on.

also I’m wondering is it better to increase my extractor fan speed at night or lower it to get the humidity down .

I know there’s no specific answers and everyone does things differently but any ideas of what you guys are doing to control your humidity at lights off would be appreciated.
 
Dontjudgeme

Dontjudgeme

Well-Known Member
Cocogrow1234 said:
during the day when lights on 12/12 my temps and humidity are perfect at 70-80f & 45-60% . When lights go out the temps lower to 60-70f and humidity rises to 70-80% .

tent : 1meter width x 0.5mtr depth x 1.8meter height so only a small space , the tent is in a small room about 2x4mtrs
6” extractor fan with carbon filter
I Don’t have a intake fan but have the vents open on the tent. (Passive intake )
lights : 2x mars hydro ts1000
I have 4 plants in total : 2 in 11l pots ,1 in 20l pot and 1 in 3l pot and there on day 1 of 12/12

i have a humidifier but it has bright blue lights on it so cannot use it in the tent when lights go out .Is there and small cheap humidifiers that doesn’t have a bright light on it ?

I have put a dehumidifier pot and bag in the tent but only done that today so no sure how effective they will be and over time the cost of these will add up so not sure this is the answer ?

I have read raising the temp by adding a heater will lower the humidity, this could be a idea as I can turn the heating on in the room the tents in , and the hot pipes are actually below the tent so kind of heats the floor below the tent when heatings on.

also I’m wondering is it better to increase my extractor fan speed at night or lower it to get the humidity down .

I know there’s no specific answers and everyone does things differently but any ideas of what you guys are doing to control your humidity at lights off would be appreciated.
Click to expand...
A dehumidifier will be your best bet. And if your exhausting out into the same room the tent is in, that won’t help either. Might need a good size dehuey too, not one of those little tiny ones, they won’t make much of a difference at all. I have something similar to this one and it keeps my tent RH in check at all times, and I keep it inside of my tent.

SHINCO 1,500 Sq.Ft Energy Star Dehumidifier, Ideal for Medium Living Room, Basement, Bedroom, Bathroom, Auto or Manual Continuous Drain, Quietly Remove Moisture & Control Humidity https://www.amazon.com/dp/B07WHXH1DC/ref=cm_sw_r_cp_api_fabc_4jiQFbV8PPB6Q?_encoding=UTF8&psc=1
 
C

chronnie49

Well-Known Member
Yea you need a decent dehumifidier. You want to put it in the room the tent is in, not the tent itself.

Ive never used those dehumidifier buckets so I dont know well they work but It would be cheaper in the long run to just get a good dehumidifier.

I forget the brand I have but it was around €150 and brings my humidity from the 70s to the 50s when the lights are off.
 
Star Dog

Star Dog

Well-Known Member
Your right enough that heat will reduce rh% a decent dehumidifier (the compreser type) reduces moisture and gives off heat at the same time, I'm running a 150w dehumidifier in my tent that keeps it at 50/52% 25c with the light on and 18/20c 58/61% with the light off, I also run an extraction fan constant slowly when the lights off and a relay/fan controls the temperature when the lights on.

If you can't keep it warm and within the right % range then keep plenty air moving through your room/tent.
 
C

Cocogrow1234

Member
Dontjudgeme said:
A dehumidifier will be your best bet. And if your exhausting out into the same room the tent is in, that won’t help either. Might need a good size dehuey too, not one of those little tiny ones, they won’t make much of a difference at all. I have something similar to this one and it keeps my tent RH in check at all times, and I keep it inside of my tent.

SHINCO 1,500 Sq.Ft Energy Star Dehumidifier, Ideal for Medium Living Room, Basement, Bedroom, Bathroom, Auto or Manual Continuous Drain, Quietly Remove Moisture & Control Humidity https://www.amazon.com/dp/B07WHXH1DC/ref=cm_sw_r_cp_api_fabc_4jiQFbV8PPB6Q?_encoding=UTF8&psc=1
Click to expand...
Thanks I will get myself a humidifier and leave it outside the tent . And yes I am exhausting into same room I do keep the exhaust fan and clip fans on 24 hours a day everyday and do have fresh air coming in from another room So hopefully won’t get into any mould issues .
 
C

Cocogrow1234

Member
chronnie49 said:
Yea you need a decent dehumifidier. You want to put it in the room the tent is in, not the tent itself.

Ive never used those dehumidifier buckets so I dont know well they work but It would be cheaper in the long run to just get a good dehumidifier.

I forget the brand I have but it was around €150 and brings my humidity from the 70s to the 50s when the lights are off.
Click to expand...
Thanks a lot I will get myself a decent humidifier.
The bags and pots don’t seem to do anything it was left in the tent for lights out and only collected small amount of water . I will try again see how it goes but I wasn’t expecting much to be honest .
 
C

Cocogrow1234

Member
Star Dog said:
Your right enough that heat will reduce rh% a decent dehumidifier (the compreser type) reduces moisture and gives off heat at the same time, I'm running a 150w dehumidifier in my tent that keeps it at 50/52% 25c with the light on and 18/20c 58/61% with the light off, I also run an extraction fan constant slowly when the lights off and a relay/fan controls the temperature when the lights on.

If you can't keep it warm and within the right % range then keep plenty air moving through your room/tent.
Click to expand...
Can I ask what humidifier you are using ? Doesn’t it have lights on it ? As my issue is with putting it inside the tent is the lights on the humidifier being on when my lights are off .
I’m going to try turning the heating on in the room tonight and see if I can get the humidity lower as the pipes go directly under the tent so will definitely give it some nice heat
. I am only on day 2 of flower so I guess I have a few days to get this right .
 
Rurumo

Rurumo

Well-Known Member
Cocogrow1234 said:
Thanks a lot I will get myself a decent humidifier.
The bags and pots don’t seem to do anything it was left in the tent for lights out and only collected small amount of water . I will try again see how it goes but I wasn’t expecting much to be honest .
Click to expand...
You need a DEhumidifier, not a humidifier. I have a new 30 pint model from Homelabs that I'm really impressed with, lowered my RH by 10% in an hour-and I have an open turtle tank. Be sure to find out how many watts the one you pick uses-mine is around 350 watts, so they aren't cheap to run.
 
Rurumo

Rurumo

Well-Known Member
Cocogrow1234 said:
Can I ask what humidifier you are using ? Doesn’t it have lights on it ? As my issue is with putting it inside the tent is the lights on the humidifier being on when my lights are off .
I’m going to try turning the heating on in the room tonight and see if I can get the humidity lower as the pipes go directly under the tent so will definitely give it some nice heat
. I am only on day 2 of flower so I guess I have a few days to get this right .
Click to expand...
You need one for the room, not the tent. Dehumidify the room that you are venting air to/from your tent.
 
R

RadicalRoss

Well-Known Member
I got a nice dehumidifier with a pump to solve a similar issue I was having at lights out. Make sure you can set it to constant and it will automatically run when power is cut and resumed, and attach it to a humidistat like an InkBird and you'll be in business. Mine keeps it at an average of 42% rh, between 39% and 50% range. I could probably turn it down even more. I just stuck the tube from the pump out the window, haven't thought about it in the two weeks or so since I set it up.

It was like a $275 investment though, so not the cheapest piece of equipment in my grow room. But also far from the most expensive, and if it saves me from mold then well worth it.
 
R

RadicalRoss

Well-Known Member
1604936872273.png

This is just set up outside of my tent. The sensor for the humidistat it's plugged into, as well as a small humidifier which barely sees use with my present conditions, is inside the grow tent. When the humidity gets 4 degrees above the set point, the dehumidifier kicks on. It'll pump water if it needs to, and then take a bit to start blowing dehudified air, but when it does it gets my tent's humidity down fast. I've never let it go to see how low it can bring my 4x4, but it gets to 39% rh from 50% in just a few minutes.

Looking at my temperature / humidity graph it actually looks like that little humidifier might be seeing some use a couple days after watering and with my light turned up to nearly max.

1604937120835.png
 
Star Dog

Star Dog

Well-Known Member
Cocogrow1234 said:
Can I ask what humidifier you are using ? Doesn’t it have lights on it ? As my issue is with putting it inside the tent is the lights on the humidifier being on when my lights are off .
I’m going to try turning the heating on in the room tonight and see if I can get the humidity lower as the pipes go directly under the tent so will definitely give it some nice heat
. I am only on day 2 of flower so I guess I have a few days to get this right .
Click to expand...
I got my one from B&Q diy I'm not sure what kind it is, I've removed the casing to make it more compact lol and put insulating tape over the lights.
It's not pretty to look at but there's no light from it and it works lol.
 
C

Cocogrow1234

Member
Rurumo said:
You need a DEhumidifier, not a humidifier. I have a new 30 pint model from Homelabs that I'm really impressed with, lowered my RH by 10% in an hour-and I have an open turtle tank. Be sure to find out how many watts the one you pick uses-mine is around 350 watts, so they aren't cheap to run.
Click to expand...
Yes sorry that’s what I meant , cool sounds like the way to go
 
Dontjudgeme

Dontjudgeme

Well-Known Member
chronnie49 said:
Yea you need a decent dehumifidier. You want to put it in the room the tent is in, not the tent itself.

Ive never used those dehumidifier buckets so I dont know well they work but It would be cheaper in the long run to just get a good dehumidifier.

I forget the brand I have but it was around €150 and brings my humidity from the 70s to the 50s when the
chronnie49 said:
Yea you need a decent dehumifidier. You want to put it in the room the tent is in, not the tent itself.

Ive never used those dehumidifier buckets so I dont know well they work but It would be cheaper in the long run to just get a good dehumidifier.

I forget the brand I have but it was around €150 and brings my humidity from the 70s to the 50s when the lights are off.
Cocogrow1234 said:
Thanks I will get myself a humidifier and leave it outside the tent . And yes I am exhausting into same room I do keep the exhaust fan and clip fans on 24 hours a day everyday and do have fresh air coming in from another room So hopefully won’t get into any mould issues .
Click to expand...
The room you have your tent in is pretty similar to mine. I tried leaving it outside the tent and it didn’t make a difference. Once inside the tent it changed everything, that’s why I mentioned inside the tent vs outside. During the winter I don’t run my exhaust as much at night because it’s cold, so the temp drops rather quickly. Once the exhaust cuts out the dehumidifier is the only thing to keep the RH in check, and it does a great job because I’m no longer exhausting/bringing in air. Bringing fresh air in the tent 24 hours a day would require the room being dehumidified like others mentioned, and you need a pretty good sized dehuey to do it. Most decent size dehueys provide the sq. footage it covers. Dehumidifying an entire room will require your tank being emptied quite a bit, unless you have the drain hose connected to an outlet source. I empty my tank max 4 times a week during flower. I’m an 3x3 tent and max out at 4 5 gallon pots inside. Don’t go cheap on the dehuey, you’ll regret it later and eventually end up paying for a good one anyway.
Click to expand...
Click to expand...
 
W

wandrew640

Member
RadicalRoss said:
View attachment 4737882

This is just set up outside of my tent. The sensor for the humidistat it's plugged into, as well as a small humidifier which barely sees use with my present conditions, is inside the grow tent. When the humidity gets 4 degrees above the set point, the dehumidifier kicks on. It'll pump water if it needs to, and then take a bit to start blowing dehudified air, but when it does it gets my tent's humidity down fast. I've never let it go to see how low it can bring my 4x4, but it gets to 39% rh from 50% in just a few minutes.

Looking at my temperature / humidity graph it actually looks like that little humidifier might be seeing some use a couple days after watering and with my light turned up to nearly max.

View attachment 4737888
Click to expand...
So do you just have your tent intake hooked up to the fan of the dehumidifier? I put one in my room but it was running A LOT and making the room very hot
 
Dontjudgeme

Dontjudgeme

Well-Known Member
wandrew640 said:
So do you just have your tent intake hooked up to the fan of the dehumidifier? I put one in my room but it was running A LOT and making the room very hot
Click to expand...
Dehumidifiers do give off heat that somewhat provides a little warmth at lights out, but not enough to drop the humidity. Running your exhaust 24/7 will definitely keep your RH in check as it’s constantly sucking the moisture out of the air. ( This is all dependent on the moisture of the air the tent is in ). Connecting your intake fan to your exhaust will be the same as leaving the dehumidifier outside the tent. It’s take a decent size dehumidifier to control a room ( depending on how big the room is ). If you have decent air flow/circulation, you’ll be fine.

NOTE! Removing the intake fan and just utilizing just the exhaust wilth all flaps and holes closed will eliminate all RH related problems as the negative pressure will make the tent look like it’s imploding from the suction ( concave ). If you decide to use this method, set your fan to its lowest setting, and make sure not to have anything in there that can fall over from the walls caving in.
 
N

nz_420

Member
Cocogrow1234 said:
during the day when lights on 12/12 my temps and humidity are perfect at 70-80f & 45-60% . When lights go out the temps lower to 60-70f and humidity rises to 70-80% .

tent : 1meter width x 0.5mtr depth x 1.8meter height so only a small space , the tent is in a small room about 2x4mtrs
6” extractor fan with carbon filter
I Don’t have a intake fan but have the vents open on the tent. (Passive intake )
lights : 2x mars hydro ts1000
I have 4 plants in total : 2 in 11l pots ,1 in 20l pot and 1 in 3l pot and there on day 1 of 12/12

i have a humidifier but it has bright blue lights on it so cannot use it in the tent when lights go out .Is there and small cheap humidifiers that doesn’t have a bright light on it ?

I have put a dehumidifier pot and bag in the tent but only done that today so no sure how effective they will be and over time the cost of these will add up so not sure this is the answer ?

I have read raising the temp by adding a heater will lower the humidity, this could be a idea as I can turn the heating on in the room the tents in , and the hot pipes are actually below the tent so kind of heats the floor below the tent when heatings on.

also I’m wondering is it better to increase my extractor fan speed at night or lower it to get the humidity down .

I know there’s no specific answers and everyone does things differently but any ideas of what you guys are doing to control your humidity at lights off would be appreciated.
Click to expand...
I just smash or tape over the small leds on things in my tent. No point having a de humidifier in the tent really, if you're extraction is all set up, it won't make much difference. I use two just in the room where my tents are, this seems to work well for me
 
Dontjudgeme

Dontjudgeme

Well-Known Member
nz_420 said:
I just smash or tape over the small leds on things in my tent. No point having a de humidifier in the tent really, if you're extraction is all set up, it won't make much difference. I use two just in the room where my tents are, this seems to work well for me
Click to expand...
I agree having dehumidifiers in the room the tent is in is effective if it’s large enough or you have multiples like in your case. I don’t need to have my exhaust running 24/7 unless it’s during the summer, at that point humidity is never a problem because the exhaust is always on. But during the winter, my exhaust runs at intervals, just when the temp gets above my threshold, and my dehumidifier is in my tent and it only kicks in when the exhaust is off. Those small cheap dehueys from Amazon won’t cut it. Of course the size of your tent matters a great deal as well. I’m in a 3x3 and have a max of 3 5gal pots growing at once. I use to think having the dehuey in the tent was pointless as well, until I got a decent sized one and it immediately changed my thought process on dehuey placement.
 
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