Indoor Humidity During Flower

[Bobblunt]

Hi All!

I have 3 DPAutoxtremes and 1 DPAutoblueberry under a 600w hps, I have a RVK L1 Fan and a CF in a 1.2x1.2x2.0 tent. They are 5 weeks old tomorrow and all healthy and thriving but ..... i have an issue with the humiditiy which i hope someone could give me some much needed advice on please???

During veg they have stuck between 60-70pc humidity which they have loved but as i am coming closer to flower them i am worried as i cant get the night time humidity any lower than 60pc.

During the day i have the intake from outside the house to cool the tent and at night i have the intake from inside the room the tents in, lined up alongside my dehumidifier which runs during the lights off period but no luck in lowering the humidity..... I also have a large oscillating fan which is as big and powerful as i could have in my tent.

Can anybody please help me!!! me no want no bud rot or mold

Thanks All

 

[Cannaficiando]

Howdy Bobblunt. If the dehumidifier can't get the relative humidity below 60%, there must be plenty of fresh (humid) air available. But closing off the tent could mean the RH goes too low, not ideal either.

I think air circulation is just as much a factor as humidity when it comes to preventing mold. My temps here are a constant 30 - 32C, and RH hardly ever goes below 60% (typically 70 - 80%, sometimes higher). Never had a mold or bud rot problem because I keep a table fan blowing over the plants 24/7.

Here's a growweedeasy.com link to humidity: How to Control Relative Humidity in the Grow Room. Hope you find it useful and good luck with the rest of the grow.

 

[Bobblunt]

Thank you for that Cannaficianado. I am trying a new method today as i want to be able to lower the humidity as much as possible for the final two weeks as I've heard that high humidity at that vital time is an assured way to have loose buds which i don't want.

Ive managed to placed my dehumidifier in the tent now and when the lights go off i will put it on full and use my fan speed controller to slow down the airflow of my RVK therefore giving the dehumidifier the time it needs to recycle the air before it gets exhausted out of the tent.

Any input from anyone as to whether that makes sense or may work?? Thank you!

 

[Cannaficiando]

Sounds like a plan, BB. But I'd err on the side of caution and monitor humidity levels initially. It might take a little fine tuning to get the balance between the amount of fresh air intake and the RH.

 

[Happy Horticulturist]

Sounds like you've got things moving foward. You're doing exactly what I would have suggested. Balancing air circulation with dehumidifier.

If you're humidity is still high when you have a dehumdifier in the room either your dehumidifier isn't powerful enough, or you are cycling/exchanging your air too quickly, or both. But the fact you said at night you don't circulate the air room to outside the room, you just keep the air circulating sounds like the dehumidifier is maybe under powered.

You could try raising the air temperatures in the room at night, because most dehumidifiers work by passing warm air over freezing cold coils and the air condenses and water falls out of it and drips into the collection tray. The difference in air temperature to coil temperature and how much water is in the air also = how much water it can extract, meaning the higher the air temperature and the higher the humidity the faster it can pull water out of the air. So raising night time air temps is something to consider trying, maybe.

 

[Bobblunt]

Thanks for all the words of advice guys! So my plan has worked my dehumidifier is running in full in the tent and main exhaust fan I've lowered to half the speed and now my night time humidity is stuck at 45pc and temp at 21.5c ..... Such a relief!


Thanks again guys! Much appreciated !

 

[Happy Horticulturist]

night 45% and 21.5c is perfect dude congrats.

Just remember in veg you want the humidity to be a creep higher, say 50-60%

Also you want your max temps to be 27c or a touch lower if you can

 

[Bobblunt]

Yeah am stoked man thank you!

Yeah day temp is 26 consistently and during veg humidity has been 65-75%

Best conditions i've grown in yet and my plants are major bushes thanks to my good friend LST haha

Excited to see the end result

 

[Happy Horticulturist]

Me too. You'll have to show us how you get on in the end. Also maybe a do a wee grow journal for your next grow. Once you have the environment dialled in it's time to start concentrating on what's going on inside the pot.

LST is good for Autos and FIM is good for the Photoperiods.

Grim Reaper and Hazy on here are both fantastic at LST you should check out their grows.

 

[Bobblunt]

Awesome will have a look at their grows today! I will upload some photos of these when they're closer to being chopped and start a grow journal next time! My plants have taken to LST so well, so bushy and multiple heads ...... Exciting stuff!