Humidity

Vizio

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Hey what's up growers? Me, I'm not doing so good. Reason being is because I can't seem to tackle this humidity issue of mine. I bought an dehumidifier & I swear that thing doesn't do the job. I really haven't notice any humidity drop. I mean it may do a lil but nothing to brag about. I have my oscillating fan & I recently added a small fan to blow air in. I have a ducting running from the AC vent into the tent. Why or where is this humid air coming from? When the light is on it seems to go down to the 40's & that's where it needs to be. But when the lights are off the humidity goes up to like 57. I'm very concerned about having mold. No the humidity hasn't reached quite 60 but how can I get it to stay in the 40's? Thanks in advance.
 

MR1

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Do you have a exhaust fan clearing the air out of your space? 40% is ok mine is at 43% right now with lights on and I don't worry. I am sure it goes higher with lights off. As long as you have good air circulation and an exhaust fan to remove the stale damp air in your room you should be ok. I have a dehumidifier in my basement set at about 55%.
 

Vizio

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My humidifier doesn't have an set range. Just plug it in & it's supposed to do its job. Yes I do have an exhaust fan pulling air out. It's an 4in with ducting. I keep the air blowing at all times.
 

MR1

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What size room do you have and how many cfm's is your fan rated for, do you have a filter in your space. When your dehumidifier is running take a look at the coils, make sure they are not freezing up, they should look wet and be dripping water.
 

Vizio

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I have an 7ft. Tall 5 ft. Wide tent. IDK how many cfm's the fan has. It's an 4in exhaust fan pulling the hot & stale air out.
 

MR1

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Is that 5' square? If it is your exhaust fan is probably to small. You want to exhaust your tent around 2 times per minute. If it is 7x5x5 you need a fan with about 400 cfm without a filter and 700cfm with a filter because a filter can drop your cfm of your fan up to 50% depending on the size of the filter. A smaller filter will drop the cfm more than a larger filter. I am pretty stoned right now so if this dosen't sound right correct me please.
 

Vizio

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Lol I appreciate the reply bro. I'm just gonna get a an bigger exhaust fan.
 

Hushpuppy

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I would say you definitely need a larger exhaust fan. 6" running about 400-600cfm. I think mine are 540cfm. I don't believe you need to be as high as 700, that would implode your tent (I know from past experience :doh: )

Where is the air coming from and where is it going to. Your plants produce moisture just like we do when we breathe. You need to remove that air coming out of the tent to a completely different location unless you are running co2 in a totally enclosed environment. If you are just dumping it into the room where the tent is located, then your dehumidifier will struggle to keep it down. Also does your dehumidifier use a catch basin ffor the water or does it run out a drain hose? If there is a lot of moisture being removed continually, then the catch basin will have to be dumped very regularly as they will fill up fast.

It is not at all unusual to have the humidity go up during the dark period as the temperature drops as "relative humidity" is the ratio of moisture at a given temp. the values go in opposite directions of each other. A given amount of moisture in an air space will show lower RH at higher temps and higher RH at lower temps. But if you are under 60% even during the dark period then you shouldn't have any mold issues. Just make sure to keep the air moving on the plants 24/7 (lights on or off).
 

MR1

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Thank you Hushpuppy, I forgot to mention a speed controller for the 700cfm exhaust fan.
 

Vizio

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Thank you HushPuppy. I have an 4in exhaust fan w/speed controller. Next week I'm gonna get an 6in fan. Don't have CO2 at the moment but going to store this weekend to pick a bag up. My air is pulled out with the 4in exhaust fan. I also have a fan blowing air in the tent. Which I think helped a lot! It's going along pretty smooth. When the lights are off I pull the AC ducting out. I didn't realize that the AC would bring humidity when lights are off but that's why it was reaching high. When the lights are on I put the ducting back in cause that 600watt has the tent pretty hot. Things are going smooth.
 

Vizio

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I have my filter on a table outside the tent. The ducting goes into the tent & pulls air out into the filter. I constantly run my oscillating fan blowing air.
 

Hushpuppy

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The AC shouldn't be putting extra moisture into the air. On the contrary, the AC should be removing some of the moisture. But iff you have a given amount off moisture in the air, then cool that air down, the humidity will rise unless the air is exchanged with dryer air from outside the room, or is run through the dehumidifier to remove more of the moisture. The AC isn't adding moisture, it just makes it look like it is going up (but its more of an illusion).

Are you removing the air to the outside world, and then pulling in fresh air ffrom the outside world? If not, you should be, unless you are changing the O2 to CO2 within the air space of the building/house. Don't buy the CO2 bags that are supposed to make CO2. While they do generate some CO2, its not enough to be worth it. To get the amount off CO2 your plants really need, you would have to have a couple off people living in the same space continually or have a propane burner that creates the CO2. It is easier and cheaper to pull it in ffrom outside. Plus you are helping to offset "global warming" by removing some of the CO2 from the outside atmosphere. :)
 

Vizio

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Thanks HushPuppy but I really don't know how I can pull air from outside due to my setup. I can't run the ducting to an window with ducting. It's just not safe IMO. Like I say it's fine for now. Like I said I have an exhaust fan pulling air out & a fan blowing air from the room in. Also the AC duct blowing cool air in from AC vent. Again I've calmed my humidity down for the most part.
 

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