Correct humidity levels

[Dr. Manny Bowles]

I've been trying to figure out what the best level is for your humidity to be at is for various stages. I've read everything from 30-85%. Seems like a pretty broad range.

What's your opinion? How high % and when?

I'm at 25-40% pretty constantly right now, temps are between 70-83, and the kids are about a week old. Is that good or not so good?

Thanks:farm:

 

[Dubbaman]

IMO 55% to 65% during seedling and veg and then 30% to 44% while flowering, sometime after the 3rd week, but thats what ive gathered in my readings and short experience

 

[smokybear]

I agree with Dubba. Over 50% during veg and around 40-45% during flower. Humidity really plays a part in flowering though. I don't worry about it during veg, just flower. Just my thoughts. Take care and be safe.

 

[Pot Belly]

around 40-45% during flower.

Humidity really plays a part in flowering though.

The lack of it does.

A low humidity at 30 to 45% is great. Any time your light is on during veg or flowering, your humidity will and should reduce to nearly those levels.

During the night cycle is when your humidity usually creeps up. Esp if you don't have a constant flow of fresh air into the space. During a 6 hour night cycle for veg, your plant shouldn't suffer too much. and it likes the humidity.

In flowering, when the buds and leaves get packed in there, and the light is off for 12 hrs, higher humidity levels increase the chances of mold and bud rot. It's best to have some sort of continuous exhaust at "night" to carry away the moisture laden air and bring in drier air for flowering. Drier air also helps in production of resin.

 

[Timmyjg6]

Nice, coming to this site every day is like coming to school.

 

[Timmyjg6]

Can you use a dehumidifier to lower the humidity. Maybe set it up on a timer?

 

[massproducer]

yeah you don't need a timer though, you just set it to the humidity level you want and the dehumidifier will do the rest

 

[smokybear]

The dehumidifier will turn off when the correct humidity is reached so the timer isn't needed. Good stuff massproducer. Take care and be safe.

 

[Timmyjg6]

OK, never had one. Was not sure you could do that.. Pretty sweet, do any of you all use them?

 

[Dr. Manny Bowles]

The lack of it does.

A low humidity at 30 to 45% is great. Any time your light is on during veg or flowering, your humidity will and should reduce to nearly those levels.

During the night cycle is when your humidity usually creeps up. Esp if you don't have a constant flow of fresh air into the space. During a 6 hour night cycle for veg, your plant shouldn't suffer too much. and it likes the humidity.

In flowering, when the buds and leaves get packed in there, and the light is off for 12 hrs, higher humidity levels increase the chances of mold and bud rot. It's best to have some sort of continuous exhaust at "night" to carry away the moisture laden air and bring in drier air for flowering. Drier air also helps in production of resin.

So I'm good? Today it dropped below 20%, the air here is very dry.
I've still been messing with my setup since I've only been "growing" for a week. I've got fresh air coming thru from under the house and venting out 24/7 at around 450cfm. The only light I have going at this point is a 400w MH and it keeps the room around 70, and the vegging area about 80. In the meantime I've been trying to find a happy medium for the humidity.

Thanks for all the replies so far:farm:

 

[Zepplin]

OK, never had one. Was not sure you could do that.. Pretty sweet, do any of you all use them?

Hi Timmyjg6,

I've been using one for the last month. I'm growing in a 3'x6'x7' tall space and have 5 plants growing. (Had 8, but three were Male.) When I started in Feb I had to run a Humidifier to keep the RH at about 50%. As the plant grew the humidifier ran less and less. Once the plants were about 2' tall the Humididy started going up to 70-80 percent.
I bought a small De-humidifier at Wally-World and it does a great job at keeping the room at 50% RH.

De-humidifier Pros: Cheap. 28qt Fridgidare for 94.99, Digital controls can set the RH from 10% to 90%. Has a built in On/Off timer., Can use the built in bucket to collect the water (24pints) or run a drip hose from it.

De-humidifier Cons: Noisy, Adds warm air to the room. (Was Running at 78-80 deg F without and 84-86 deg F with - thats with light on). Have to empty the bucket every day.

All-in-all I'm happy with it.

Hope this helps,
Zepplin:fly:

 

[Pot Belly]

So I'm good? Today it dropped below 20%, the air here is very dry.

Yes - your dry humidity is fine. You will have to check your plant grow medium to make sure it doesn't get too dry. As long as you keep your plant hydrated, low humidity will be fine.