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Having trouble getting RH down into the 50's

mazda3234wd

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Hey guys.
I am back growing again after a 2 year break.
I wanna try and fix a few problems ive always had in my flowering room, which is Humidity will not go under 65%.

I have placed a de humidifier in the room which got me from 76% to 65% but I wanna get it into the 50's

Now a bit a run down on the room. Its under the house and this house has been build around sand stone so the whole under neith of the house is like a cave system, theres heaps of room under there so I turned a bit of it into a grow room. Now I think I know where I'm going wrong...
The room is not at all seaeled, due to the rocks its damn hard to seal it up 100% I've done what I can. Now the bad side to this cave world is It has drains that run through it so under the fake floor I've built there are drains that run when it rains.. Is that what could be stuffing my chances up of getting to 50%RH?

Another thing i wanna add since it just poped into my head... I have 2 x 50 L res's under my coco tables that do not have lids.. Could they be effecting my RH?

I've read that some people but bags of rice in there grow rooms? has anyone ever heard of this?

I'm lost guys, If anyone has any suggestions about how I can get the RH down, I'd love ya forever!

drain is under there.JPG


gauge.JPG


Room pic.JPG


The big cold rock.JPG
 

Coho

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Yes can you move the reservoirs outside the tent? Get lids?Whats the RH the room?Seal the floor with plastic. Sounds like a great wine cellar-
 

OGKushman

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got to seal it with plastic and dehumidify the intake. This is going to be fun to watch (no offense at all). I really want to see this happen.

:peace: good luck brother and keep us informed! :)
 

PartyBro420

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the rice does work yea, but also being in a basement type area having food may also attract mice/squirrels/other rodents and pests that might decide to also destroy plants and electrical equipment.

I'm with OG on this one, Seal the stone with plastic vapour barrier. I'd also suggest to wrap the cold water pipes in the same barrier or some sort of insulator. It really looks like the biggest problem is gonna be that stone though. Definitely cover any of the exposed rock in the area up with vapour barrier. Sandstone holds a lot of moisture when it's available.

Looks like a fun place to live though for sure, i wish i had a cave in my basement.
 
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What kind of exhaust system do you have set up?

IMO, your res should always be covered for reasons other than humidity (insects, dirt, etc, etc), but yes, 2 large vats of water are going to evaporate if not covered and raise your RH.
 

suburban

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Just going by the details you provided and the pics, IMO you need a closed off space (at least for flowering) and probably intake air from your house (or from somewhere of lower humidity where the humidity range won't swing from low to super-high). I don't know where you live, but with all that porous rock surrounding your area, you're completely at the mercy of soil saturation/weather conditions. And I don't think finishing/sealing off that entire space looks doable (?) A big enough humidifier MIGHT keep up, but who knows.

How are temps in general? What kind of height restrictions are you working with?
 

Iron Emmett

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I cant help in anyway that hasnt already been suggested, but i wanted to comment on how cool of a grow that is, you grow in a cave, thats awesome.
 

mazda3234wd

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Thanks for the reply guys.
I went to the hardware shop and got some foam gap sealer stuff and went around and filled in all the holes around the grow room, which has helped a bit.

I wasnt actually running any fresh air in so set that up too and now RH is down at 65% depending on outside temps I saw it go down to 60% yesterday so I believe I'm on the right track now.

Only thing I'm a bit worried about now is temps are 28c at the plants and 26c at roof. Is this getting to high or am I ok until 30c +

One other question i had which is regarding the same thing. ( I think )

With my exit air, I have a big 250 centrifugal fan sucking out but where it comes into the grow room I have it splitting off into 2 x 150's which are running straight over the lights. Do you think I'd get more exit air if I took the x 2 150 splitter out and just had the 250 sucking?

Reason I ask this is before I setup the air in everytime I'd close my grow room door (piece of panda film) the door would suck into the room. Now after I ahve set intake up the door pushes out... I believe it would be better if the door was sucking in yea? rather than pushing out.. that tells me the room is recieving more air in than air out????

Someone asked how much head height I have... there is around 4.5 meters in the flower room...

Cheers once again for your help people!
 

OGKushman

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-60 is still a wee bit high, but yes you are on the right track. Mold is possible in denser buds at that high of a RH, but if you take some preventative steps to keep boytritis and powdery mildew from flourishing then I think you will be good to go.

-30 degrees C is a little too high. Aim for 23-25c

-YES! Unplug whatever is holding your fan back. 250CFM is small and it needs all the help it can get to clear your grow room. Blow fans on the bulbs if they get too hot. You may need 2 fans.


Doing good brother!:D
 

Coho

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Maybe get some moisture sealing paint or concrete sealer and cover the stone in there. Also is the air good RH outside? Maybe pull air in.
 

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