My girls are 2 weeks and a few days into flowering. Humidity looks high to me, charts online seem to differ in the proper values I should keep.
I pruned them about a week or more ago. Looking at the pictures, should I prune a bit more to help lower humidity?
Humidity is now 68% temp 22.7c, as you can see from the picture.
I have to close the tent for about 5 hours out of the 12 the light is on, so humidity is going to rise further.
I bought a couple of disposable dehumidifiers, and it looks like they do nothing. They are still dry after 2 days in. I’ve got 3 fans and a fresh air intake going, plus the exhaust filter.
Thoughts? Pruning or not? Another fan? Is the humidity at 69% very high or still ok?
5 plants, 120cm square x 180 cm tent 420w light
Thank you guys
Passive dehumidifiers won’t keep up with an ongoing humidity issue. If you need to lower the RH then invest in a real dehumidier. Get one that has a drain hose so you can drain into a 5 gallon bucket.
Temps are fairly low for the high RH. If you have a charcoal filter on your exhaust: remove it. That will increase airflow. BUT! If your input RH is already high there is not much else you can do but add a dehumidifier.
n.b. I removed your profanity. Please refrain from that on this forum
Sure, sorry, i thought thry were allowed. Thank you for the advise. A dehumidifier is too expensive right now for my means.
I think i know why temperature it’s relativity low compared to humidity.
England in’it? been raining on and off for 2 days, 81%RH outside
I agree with @Myfriendis410 a commercial dehumidifiers the only way to go. Don’t waste your money on those $40 $50 Amazon ones. They’re not going to work
It’s not a cure all but I played around with my can and inline settings and it got mine to lower by around 5%. I’m just about to where you are besides higher temp. Ohio isn’t ideal when it comes to humidity but I make it work. Fighting mold on my substrate but thankfully none on the plants themselves. It’s a very tricky formula between heat, airflow, and humidity.
Also! I got a small heater and placed it under my table that I have my plants on and it lowered it by AT LEAST 5% max 10%. Just be careful because it obviously does raise your temp.
Best of luck! Tag me if you need any help. I’ll do what I can do to help
I’d like to preface that Im new to cannabis and on my first grow.
Ive been doing a bunch of research on humiduty the last few weeks myself in forums, articles, and some science papers. I know many will recommend 50%. However as long as you have good air exchange you should be ok. Some larger growers even aim for 60% to 70% throughout flower. Again, good airflow/exchange. Powdery mildue some claim to be caused more by large swings in rH than just high levels and can even occur at very low humidity with again, poor airflow/exchange. Bud rot can also be kept at bay in higher humidity the same way. Again, just going by a bunch of reading I’ve been doing but without personal experience as others here will share.
I read people say a higher rH is better on the plants and also uses less nutrients and water as the plant doesnt need to transpire as much. I recently let my tent rH go up to 60% and she is in early flower and still stretching. I’ll likely keep it this way till harvest and dry. I do have a large 70 pint dehumidifier running which can easily pull 3+ gals of water in 24 hours or less when trying to achieve 50% in the room my tents are in. Its not a typical lung room so not enclosed with doors. So I’ve given up on running that thing 247 to save on some energy and see how it goes.
So do what you can to keep it acceptable and make sure again, good airflow and exchange. You might be able to find a large dehumidifier looking on fb marketplace or a thrift shop. They can be quite expensive mine was over 300 bucks but had it from a few years back .
AC u know im dealing with the same region as you and being October and the tail end of a hurricane aint making things any easier is it?!
Mine got into the 80s last grow, thought a cloud was going to walk out of the tent one day
3 fans, lots of fresh air, make sure she dries out fully.
I got a full sized dehumidifier in LIDL of all places for 100 quid, but it was reduced down. Them and Woodies seem to be the most reasonably priced ones, Woodies has new ones in stock varying from 150 up.
Have one fan blowing over the top. One that blows over your soil, and one thats hitting into the middle of the plant. Make sure you’re not bombarding the plants, the leaves should slightly dance.
Have you heard of the “flying tiger Copenhagen” shops? Their the little quirky white shops that sell random brick a brack?
I’m sure it’s just coincidental but mold and Bud Rot seem to be reported this year at an all-time high both indoor and outdoor.
Humidity’s been in an all-time high this year in our state. But so has the temperature. We normally average 80% humidity and 85° temperature during the peak of Summer. This year we had triple digits through the entire summer and an average of 95% humidity.
I’ve been getting an average of 3 gallons a day water from my dehumidifier which I pour in 5gal buckets to feed my girls with. (That should tell you how humid it is)
There’s so many people ask, what are the most important things to get when starting your first grow.
1.) the best light you can afford and then spend a little bit more.
2.) A commercial dehumidifier
(There is no substitution)
3.) reliable heating and Air conditioning easily accessible to your tent. Powerful enough to heat or cool a lung the room.
Everything else can easily be purchased in a more budget conscientious situation.
I agree with you about humidity being off the charts this year, esp when the temp was also really high. I’m not sure if anybody will approve my theory, but as a retired horticulturalist I know the importance of air flow around plants. To facilitate that, I started removing some fan leaves early in the season, being really certain about nutes since you are slightly altering the way the plant can photosynthesize by removing fan leaves. But it did increase air flow, and stopped the powdery mildew that was beginning to show up. Cut those leaves off too. I think we all have to learn to adapt to the new weather patterns, as much as I hate to say so. I grow outdoors, have about 24 years experience, not that it counts for much if Dame Nature is not going to cooperate!
Hello, @Sandbie; sorry about the late response; it was an ugly day for me yesterday.
That was one of my questions if I should cut more leaves. For now, I’ll do that and keep an eye on RH.
Market place on FB can be very good.
My friend is an idiot and sent a £500 item without any garantee, and never saw a dime. That’s his fault anyway, £500 (who was worth £2000) item either collection only or take every precaution.
Hey, thank you for the input. I have a “glass heater”, not sure how else to call it; it was part of a second-hand bundle I bought from an ex-grower. It looks like a long glass light tube, but it’s a heater.
It’s dry heat best for cannabis plants in a tent? It probably is, like you said a mat or this glass heater.
Atm temperatures are still ok, but soon I’ll need to introduce a heating element.
A couple of times the temperature went down already, and I blew some hot air in from the intake airflow tube guess it wasn’t the best idea?
The glass heater I have to connect it to an INKBIRD thermostat, which I have, but I can’t be bothered to set it up .
been raining on and off for 2 days, 81%RH outside
for 12 hours 
Best of luck! Tag me if you need any help. I’ll do what I can do to help
