Cant get Humidity down

I'm having a problem with 70% humidity, I cant get it below this during lights off (on 12-12) if it has been raining outside.

Im using a DR240w tent with 8inch exhaust and 6" intake. Intake is on full and exhaust is about 70% (both on 24/7) with 3x oscillating fans on also ( 2 on 24/7 on canopy, the other on 12-12 between lights and canopy), temps around 68F-71F during lights on and around 62F-66F during lights off. If it hasnt rained in a few days I can get it to go down to about 60% humidity during lights off, but when it rains (which is often here) it goes up to 70% during lights off. I afraid to turn the exhaust up too high as it bends one of the poles in the tent that is holding the carbon filter up as the tent sucks in Outside humidity is about 70%+

I cant afford a de-humidifier at the moment and I ran out of gas in my gas heater, cant get that refilled for awhile either. Is there any cheaper methods to reducing humidity? Ive heard leaving a bowl of rice in the grow space, does this actually reduce humidity much? Any other cheap methods?

Any help appriciated.

i know that chalk absorbs moisture. but dont know how you would go about placing it. unless u see moisture some where.

No i dont see any moisture, its really just in the air as the outside air is humid that it is pulling in.Have you used chalk before?

ya but i had a little moisture on parts on the ducting.

Ah i see, im looking for some method to take it out of the air.

You might want to try DampRid. Maybe two of them. Can find at Home Depot $3.. Get the cup version.. Also, have you tried putting your carbon filter at the bottom? (standing on its side)

I had the same problem. Had to keep fan on 24hr and used DampRid.

Im not in the US, but i'll have a look for damprid in local hardware stores i suppose. I was always told to have the carbon filter at the top so it can suck the hot air. Would it work just as well standing on its side on the floor?

It really depends on which one you have. Mine works fine standing in the corner. (I attached it to one of the post so it does not fall over, its pretty stable)
I have seen people put the carbon filters at the end of their out-take (outside the room, using the fan to push the air through instead of pulling)



You pose a great question and I would love to hear other takes on this also.

Another suggestion... Maybe get a de-humidifier for outside the tent... If your tent is passively pulling in air like mine, you might want to try to control that environment since the air is going in your tent anyways.. Just a suggestion.. Good luck.

48martin said:

Another suggestion... Maybe get a de-humidifier for outside the tent... If your tent is passively pulling in air like mine, you might want to try to control that environment since the air is going in your tent anyways.. Just a suggestion.. Good luck.

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I cant afford a dehumidifier at the moment as stated in 1st post also i have a 6" intake not passive intake also mentioned in 1st post. I'm looking for a cheap solution to reduce humidity

48martin said:

It really depends on which one you have. Mine works fine standing in the corner. (I attached it to one of the post so it does not fall over, its pretty stable)
I have seen people put the carbon filters at the end of their out-take (outside the room, using the fan to push the air through instead of pulling)



You pose a great question and I would love to hear other takes on this also.

Click to expand...

I have a 8" Rhino pro air filter - one of these ones - http://www.greenshorticulture.co.uk/Grow-room-Products-20/Carbon-Filters-Odour-Control-300/Rhino-Pro-Filters-Pre-Filters-1271.asp

It weighs a LOT, so I would prefer to have it on the ground, but it is on the same side as the intake, so I'm afraid it will just pull the intake air straight out through the exhaust without circulating around the tent. Is anyone else using a DR240w tent that has their carbon filter on the floor? Pushing the air through the exhaust isnt ideal either, its always recommended to put it inside the grow space and mine is exhausting out a vent, so I wont be able to do that if the filter is on the end

Sorry.. It was a couple of days since I read the OP... Just trying to give you some ideas.

48martin said:

Sorry.. It was a couple of days since I read the OP... Just trying to give you some ideas.

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LOL i only wrote the OP a few hours ago Its ok though mate appriciate the info, not having a go.

bump.. anyone any other suggestions?

get a dehumidifier for cheap, not the electrical ones but the cheapo ones have a look online ill try get a link for you.

http://www.ebay.co.uk/itm/LARGE-INTERIOR-DEHUMIDIFIER-DRAWS-IN-MOISTURE-STOPS-DAMP-MILDEW-CARAVAN-HOME-/280813840555?pt=UK_Home_Garden_Hearing_Cooling_Air&var=&hash=item4161cf28ab
have a look for somthing like this, if you're in the states you will have to find another link, but its pretty cheap, i found out about these from my aunt and they do work pretty well for the condesation on windows, so if you get a few im sure you could take the RH down a fair bit.

iiKode said:

get a dehumidifier for cheap, not the electrical ones but the cheapo ones have a look online ill try get a link for you.

http://www.ebay.co.uk/itm/LARGE-INTERIOR-DEHUMIDIFIER-DRAWS-IN-MOISTURE-STOPS-DAMP-MILDEW-CARAVAN-HOME-/280813840555?pt=UK_Home_Garden_Hearing_Cooling_Air&var=&hash=item4161cf28ab
have a look for somthing like this, if you're in the states you will have to find another link, but its pretty cheap, i found out about these from my aunt and they do work pretty well for the condesation on windows, so if you get a few im sure you could take the RH down a fair bit.

Click to expand...

Its almost 2 years later, I think hes probably good at this point.

iiKode said:

get a dehumidifier for cheap, not the electrical ones but the cheapo ones have a look online ill try get a link for you.

http://www.ebay.co.uk/itm/LARGE-INTERIOR-DEHUMIDIFIER-DRAWS-IN-MOISTURE-STOPS-DAMP-MILDEW-CARAVAN-HOME-/280813840555?pt=UK_Home_Garden_Hearing_Cooling_Air&var=&hash=item4161cf28ab
have a look for somthing like this, if you're in the states you will have to find another link, but its pretty cheap, i found out about these from my aunt and they do work pretty well for the condesation on windows, so if you get a few im sure you could take the RH down a fair bit.

Click to expand...

Those style of dehumidifiers are rubbish. They cant handle a grow room. I got sorted in the end, I upgraded my intake to 8inch