Humidity problems even with humidifier

[Xorbex]

I'm having issues getting my humidity above 35% and being a first time grower it is making me nervous.

Here's my setup.

48x48x80 grow tent
2x 1000w led lights
4" fan with carbon filter and ducting
Filtered 4" duct air intake
Ceramic heater
Humidifier meant for a small/medium room

The humidifier is doing its job cause I can see the vapour and my fan is on its lowest setting. Max output is 190cfm. What can I do to get the humidity lvl up?

 

[Old Salt]

Humidity levels will change throughout the day. It is usually highest about an hour or two after the lights go out, and lowest at lights out. This is due to the heat of the lights. You can draw damper air in, or hang damp towels with the ends in a pail of water. A fan blowing over the towel will help.

FYI the water carrying capacity of air doubles with every 10°C (18°F) increase in temperature. This means that if the humidity is 70%, and the temperature goes up 10°C, the humidity will drop to 35%, providing nothing else changes.

It's a bit of a conundrum. You need air for your plants, but replacing the air in the tent gets rid of the humidity you are trying to add.

 

[Xorbex]

Humidity levels will change throughout the day. It is usually highest about an hour or two after the lights go out, and lowest at lights out. This is due to the heat of the lights. You can draw damper air in, or hang damp towels with the ends in a pail of water. A fan blowing over the towel will help.

FYI the water carrying capacity of air doubles with every 10°C (18°F) increase in temperature. This means that if the humidity is 70%, and the temperature goes up 10°C, the humidity will drop to 35%, providing nothing else changes.

It's a bit of a conundrum. You need air for your plants, but replacing the air in the tent gets rid of the humidity you are trying to add.

Ok so as suggested I hung 2 medium towels with a 6" clip fan on low. Also purchased 2 new rh meters. One analog and one digital. The new ones are reading 54% while the old is 35%. It seems the original temp/rh meter is not accurate at all.

 

[Hdinkleman]

Ok so as suggested I hung 2 medium towels with a 6" clip fan on low. Also purchased 2 new rh meters. One analog and one digital. The new ones are reading 54% while the old is 35%. It seems the original temp/rh meter is not accurate at all.

humidity is going to be the air pulled into the tent thrpugh the ducting when you have an inline fan pulling 24/7.
get a humidity controller and adjust the fan to turn on and exhaust the humid air out instead of running it 24/7 is the only way.
my humidity stays around 30%
i dont bother with it, i keep my inline on 24/7.

personally i wouldnt worry about it

i have done the hang a wet towel on a rack in the past, and i have a humidifier now that if i remeber i will turn on and set at the lowest setting during lights on.
even with it on hunidity doesnt budge, its all getting sucked out the carbon scrubber.
this grow i finally stopped giving a F about it, maybe i wont max out my plant but the two i got in my tent now dont seem to care

 

[Old Salt]

This same issue was mentioned in another thread. Here's my comment.

 

[SLHLover]

I use a 1metre x 1 metre tent in a space of approx 6sq metres area. I find it easier to control temps and humidity by controlling the air in the space OUTSIDE the tent. If you can do that then the air sucked into your tent will be the right range.

 

[Xorbex]

I use a 1metre x 1 metre tent in a space of approx 6sq metres area. I find it easier to control temps and humidity by controlling the air in the space OUTSIDE the tent. If you can do that then the air sucked into your tent will be the right range.

I may try setting up the humidifier on the intake. I have a 8' length of 4" ductwork with the inlet being a dryer vent (one that would normally go on the outside wall of your house) Only concern there is that it would turn into water in the duct.

 

[bobrown14]

Your humidifier is working and your humidity is in the 50% range temps in the 70's??

That's about as good as it gets.

Id turn OFF the humidifier and see where the RH goes.

More often it high humidity that is the issue unless you live in a desert.

Eventually the plants will transpire a lot more - if you water enough. That raises the RH significantly specially at lights out. So IF you want more humidity - water your plants more. The plants will regulate the RH much better than we can. They like it humid not dry, so water them and they will transpire and raise the RH.

Get a RH/temp meter that stores your highest temp for the day and the highest RH for the day.

Google "ThermoPro TP50 Digital Hygrometer Indoor Thermometer"

There's a million out there but this is what you want. Get 2 so if one is off you prolly need to change the battery and won't find out after its too late.

 

[Edzzed]

What I did to increase humidity was put a damp towel in front of an oscillating fan. Picture a 5 gallon bucket 1/2 full of water with two 10x20 inch face cloths hanging from a coat hangar. I had an aquarium pump pipe water to wet the towels every half hour. Pump would run for 2 minutes at a time. Took a needle to make holes in pump line where it was wrapped in towels. Got humidity up so much that I had to get a dehumidifier to keep levels in check. You can see hoses in pic.

 

[bobrown14]

Thats how we do AC at "the camp" with no AC in the summer lol. It works.

 

[Xorbex]

Turns out a inaccurate meter was causing issues. Temps are between 70-80 now and humidity 65ish rh. Added a 6" clip fan to move air around plants and through vapor. Humidifier now on high to accomplish this, when on low its 50ish rh. Also its cold and dry here now and with everything off its a solid 30rh. Using a Ceramic heater to control temps but also messing with my rh. Things should stable out as the outside temps hit more than 5C.

 

[bobrown14]

65RH is the upper limit for me and I like it in the 50's RH better.

If temps are in the 70s there's a pretty wide range of RH sweet spot.
As temps go up the RH sweet spot gets more specific.

Keep temps in the 70s and you can turn off you humidifier.

Run fans on the plants, the leaves will transpire enough water to regulate the RH where the plants like it. As long as you are watering enough.

 

[01way]

Will have to try the two towel trick as I do live in the dessert so... single digit humidity is a norm

 

[bobrown14]

Yeah it works great. Just get a nice size fan on the towels and blow direct into the plants. It has a cooling effect as well so watch the temps at night.

Thats a hillbilly AC unit right there.

My wife taught it to me last summer was hot a/f in Ontario - we had no AC was 115F in the SHADE. Had towels, bucket and fans. bingo

I was wiped out. Didn't even want a beer. It got me and our pups thru the afternoon bake. Worked amazingly well.

 

[Wulves]

I'm having issues getting my humidity above 35% and being a first time grower it is making me nervous.

Here's my setup.

48x48x80 grow tent
2x 1000w led lights
4" fan with carbon filter and ducting
Filtered 4" duct air intake
Ceramic heater
Humidifier meant for a small/medium room

The humidifier is doing its job cause I can see the vapour and my fan is on its lowest setting. Max output is 190cfm. What can I do to get the humidity lvl up?

I have a Cool Mist Humidifier and 2 Vicks Vaporizers going.
The combo of the Cool Mist keeps things from going crazy because those Vicks Vaporizers kick.
I get 50 degrees to 55 all day and at night .
They need refilling every 4-6 hrs though.
But they do the job.

 

[Wulves]

Turns out a inaccurate meter was causing issues. Temps are between 70-80 now and humidity 65ish rh. Added a 6" clip fan to move air around plants and through vapor. Humidifier now on high to accomplish this, when on low its 50ish rh. Also its cold and dry here now and with everything off its a solid 30rh. Using a Ceramic heater to control temps but also messing with my rh. Things should stable out as the outside temps hit more than 5C.

I didn't think to ask if the meter was malfunctioning. Lol

 

[bobrown14]

I have a Cool Mist Humidifier and 2 Vicks Vaporizers going.
The combo of the Cool Mist keeps things from going crazy because those Vicks Vaporizers kick.
I get 50 degrees to 55 all day and at night .
They need refilling every 4-6 hrs though.
But they do the job.

What are we growing in 50-55F all day and night??

 

[Wulves]

Autos Afgan and a North Lights.
And an unknown strain.
I found the seed in my bag of top soil nameless for obvious reasons.
Lowering the humidity this week they are in the preflowering stage.
But it's so friggin dry here omg!