Thanks
@Jon, I have a question: I have quite high humidity around 70% when the lights are off, I don't know what to do with it? I noticed that you have an air extractor built on the ground in your tent, does it help with moisture? Today I have already turned on the light 100% so maybe it will also help and I also have a dehumidifier there.
Hi
@Kanno26 - the air extractor you're referring to is simply a common window air conditioning unit for standard sized windows. Specifically it's a 5000 btu AC unit with high/low AC and high/low FAN ONLY settings. I used to use an 8000 btu digital one (bigger, had dehumidifier function) but the digital system had issues. These work amazingly well. I use them for two reasons -
- they will help keep temps down
- they will help keep humidity down
One of the ways an AC unit cools the air is that it takes water out of it. So you're taking in the outside air and shooting cold and drier air into the tent. It's also relatively easily controlled with the exhaust fan if you have variable settings. On the lowest setting, more cold air stays in for longer, and the effect is more pronounced. As you get higher on the exhaust setting, the effect gradually declines.
They work very well in both veg and flower but there are a few VERY IMPORTANT infrastructural differences you need to know:
- In veg, when light leaks are not an issue, there is no need to seal the AC unit to the tent. See picture #1 and #2. In the first you see what I mean about having the unit on an angle. In the second you can see how little of the actual vent I have going into the tent right now. This has me at 75.6 degrees and 57% humidity, which is just fine as a compromise environment for one plant budding and the others in seedling. You can change the angle of how the unit hits the tent however you wish. By working with this and a combination of opening tent doors a bit or whatever, it becomes very easy to customize your veg environment. If you need it colder and drier, you put the unit square on to the rectangular port so that both sides of where the air comes out are blowing in and you're minimizing the warm air draw.. If you want it less so you do something like I pictured. Change the angle so less of the air is blowing in and more is wasted outside the tent (you don't care about that). A 15 or 20 degree angle change will change your environment and it becomes easy very quickly. This works for the entirety of veg.
- In flower, you have to make a change. You can't have light leak where the unit meets the tent. See picture #3 and #4. In the third picture you can see how I light seal. In the fourth picture you can hopefully see the rolled up black sock thing I do to seal to the tent. This is your most important seal - you don't want to compromise the air coming in or the holes under the vents on the front as this is air intake. So you only have a strip a few inches wide to seal it, and you have to do it while you can look at the inside of the vent to see what you're doing. Sounds harder than it is. This has me at 73.4 degrees and 41% humidity this very moment and the RH will go down as the day goes on - right where I want them for flowering. This is the AC on the 3x3 for the Apple Blossom. Note that I have sealed light but allowed the vents of the unit to remain exposed so as to not compromise it's air intake/outflow. So all you're seeing is the AC unit square to the rectangular port and centered on it, with black clean (lol) socks that I rolled up to seal the vertical space between the unit and the tent, and then various other things (the scarf, brown towel, piece of wood, etc) to make sure it's sealed. It's good to test the light seal to make sure you got it all. Once you do this you will not have the option to change it really anymore. I break it down once a week, dump any water out of the bottom of the unit, let the compressor rest a bit, and change any setting I need to on the unit then set it back up. It will keep down the temp and the humidity and is the only reason I can get to mid 30s RH ever on either tent.
A unit my size (5000 btu) works well for a 3x3 or up to 5x5. Anything smaller it's too much. Anything bigger I'd use a bigger unit.
I am a big advocate of this practice and have experimented with several methods since my first grow. Hope this helps, but if you want to get even more radical I have other tricks up my sleeve regarding using these units, just lemme know.
Good luck!
