Hi all! I've been lurking a while, and I've finally (sort of) started my first grow and tent! I've run into a couple of issues regarding ventilation, however, and can't seem to understand why. First off, I'm running a Secret Jardin DR120II tent, with 6" Blockbuster reflector, and 6" Hurricane inline fan, and 6"x24" Phresh filter. The ventilation runs as follows: Filter ---> Duct ---> Reflector ---> Duct ---> Fan ---> Out. The room is A/C'd, with ambient temps between 59-63F. I've got two intake ports open for passive intake, and I've definitely got negative pressure. I've seen people with higher ambient temperatures, and smaller inline fans achieve lower temperatures than I'm managing, which sit between 79-83F inside of the tent with everything running. I've included a couple of photos so you can see what I'm talking about. I can't make sense of it at all. By the way, my light is presently hanging 24in above the thermometer. Thanks everyone, and happy growing!
Update: after two hours of running, the temperature is up to 87F, and I'm expecting it to rise now. Ambient temperature is presently 59F. What?!! Update 2: two and a half hours in, and temperatures are 90.4. What is wrong with this setup? I've seen far worse than this outperform the hell out of mine, and I'm beginning to get frustrated.
Just wait till summer arrives, better to scale back that 1000 watter to 600 watts, something a noobie can handel,....or continue LURKING....lol!
Yea man. Turn your lamp down. Raise the light. Make sure your vents are open. I run 2k in a 4x8 with ancients at 63 and am able to maintain 80 degrees. You may have the movement covered with your inline, however if the air isn't able to enter the tent and cycle then your temps won't stay in check. Also run a 1000w in my 4x4. Highest I can run it is 75% for temps but that's with a 4" fan.
Thanks for the smart ass replies but I'm actually looking for information that helps. I've seen plenty of grow journals with 1000w lights in 4x4 tents, and I've seen plenty of journals where ambient temperatures are within 5 degrees of the tent's temperature. I'm only looking for some advice from the more experienced growers that might be available here, as I have no one and no where to ask where I live. How is it that people are maintaining reasonable temperatures? Four hours later temperatures are right at 93F, with the ambient temperature of the room hovering at 61F. Why is there such a massive difference? I would vent into a separate room, but if ambients are fine I don't see why it should matter. I don't want my plants to stretch terribly, and isn't 24" above the canopy still too far already? There aren't even plants inside yet, as I'm trying to sort of calibrate everything, but the light eventually will have to sit even closer to the canopy, right? (Grasscity seems like a great place to make posts, get 300 views, and one or two worthless responses, c'mon guys.)
I have the light totally enclosed with a 6" pulling air from the room through the tent then through the floor to basement..then i have a 6" that sucks the air out of the tent and blows it out a can 33 it sits on top of..i know its better to suck through but it works fine..usually stays round 78-82 (running at night) even last summer when it was 90 all month it only got to 87..i also run 8000btu ac but in michigan its cold most of the year so thats nice
Ok, their is a scale that was floatin around. I'll post it when I'm back to my computer. I think a 1k mh is like 30" from canopy. Hps runs a bit cooler so could be closer.
Thanks for the helpful responses guys, and if in fact MH runs a bit higher than HPS and a bit hotter that'd help a lot. I've also realized my A/C has been misreading ambient temperatures, and adjusting it's power as such. Upon measuring the room with my thermometer I've found it to be in the 80-85 range, making the actual difference in ambient and tent temperatures very manageable. I plan on venting the light outside the house, which hopefully will fix the A/C ambient misreading, or at least make the A/C accurate at it's 65F display. If so, my tent temperatures should be between 74-78, which is ideal enough. I'm using Co2 bags, and supposedly that helps raise the photosynthetic temperature too! Thanks again everyone, although continued advice may very well prove beneficial. I'll update soon!!
Every grow is different. I wouldn't go by a set amount of inches. I prefer the hand test. If its uncomfortable for the back of your hand, it's uncomfortable for the plants.
Update: I've run ducting outside, and have ran the light for about an hour now. Ambient temperatures are sitting around 65F, with the internal temperature (right now) at 83F. Much closer, but perhaps I'm still doing something wrong? You've seen the pictures, does it look correct? From what research I've done, unless I've screwed up the ventilation somehow, my temps should be pretty much in the ideal range. Any ideas?
Sounds like vegging with your HPS is going to be the way to go. I've given up on running MH personally. 83 sounds reasonable though
The temperatures in the room have equalized at 79.0, ambient temperatures about 60F. However, the light is about 30-32 inches from the theoretical canopy. Will this create a stretching problem during the vegetative cycle? And, does supplementing Co2 help with elevated temperatures? Is HPS effective for vegetative growth? I'd rather just drop down to the 75% power on the ballast if that'd be more effective for growth and temps. Keep in mind I'm not actually running an oscillating fan inside the tent at the moment. Would this make any noticeable change in the temperatures? Or should I switch to HPS? Or lower the power setting on the ballast? Orr... I guess just leave it as is; 79F doesn't seem too bad. It grows outside in high temperature environments just fine.
I would increase ducting and fan size. Sounds like everything you have is working crazy hard. If you got the $$ then get a window ac tape a box over the outake of the ac. this could take a little creativity then cut a hole slightly smaller and force you tubing in there. You wont need and intake if you do this and im assuming you have a nearby window. Vent the heat out into a different room if I was you I would vent it under the house to avoid FLIR. attach your filter to the outake fan and you should be solid. If you do this then the ambient temp does not need to be as high. My friend in colorado does this exact thing. his ac is set at 68 and his 76 inch all the way around is 74 degrees. When I go out again I will take pics. He uses one AC to cool his single 1000 watt MH with two outtake fans one attached to carbon filter and one just taking out heat. They come together at a T and vent out under the house. The ac blow down into a T and its rigged to where a small hose brings in cool air to cool off the general grow and the bigger vent run to the light. Using an AC can be expensive but they can also be used to put on a timer. TIme it to go off 15 minutes after the lights to get a nice cool down for sleepy time lol. Everything wrote here is pure fiction. Im just bored.
The oscillating fan blowing right over the top of the canopy will blow heat away from the plants and the wind can help increase plant structure and they grow stronger due to the wind. HPS has more lumens but the spectrum isnt correct. I knew someone vegging under a about 8 T5 with a HPS in the room and he would swear that the plants didnt like it when they were small. If you are growing sativas I might look into topping or FIM personally I would FIM and LST to reduce verticle growth. Stick with the metal halide and then switch to HPS or a conversion bulb.
Man toss those co2 bags in the trash. Not gunna do shit for you. They don't creat the ppm you need. If you wanna fuck with co2 get a burner. Baby steps bro. Get a few complete grows under your feet before you worry about all the bells an whistles. I mean your having a 2-3 day temp issue. I dot think co2 is in your near future. You need everything else in check before co2 can even begin to help.
I don't think it should require years of growing just to dial in the settings needed, a few days at most. I've stabilized temperatures at 76-77.3F, with 30-35% humidity. I'm aware to Co2 bags might not be as ideal as a burner or some elaborate contraption, but I know for a fact they will raise the PPM to some degree in the room, and for the price why the hell not? Even a couple hundred PPM is better than not, amirite? I'm not sure this FLIR thing can be a huge issue. Supposedly the tent has some kind of IR blocking layer, and people vent dryers, don't they? Grow tents are not the only thing that emits heat, and it's probably cooler than most of the rooms in this house anyway. But, more information on FLIR cameras would be useful. Would it be a good idea to rent one from Lowe's, and check my house out? This isn't a massive commercial grow, just a relatively small person one. Update: Temps lowered to 73F, have since lowered the power of the A/C and put it in energy saving mode. Temps have leveled off at 76.3F, with the A/C running on low. It looks like I'm good to go. By the way, my one Co2 bag raised the PPM from 400 to 900, which I deem to be a significant increase. Suck it, nerds! Thanks everyone for the help though, it was much appreciated.
Just though I'd post one more update, and maybe I'll start a grow journal next; I've stretched out my ducting, and now the 1000w MH sits just 14in. above the canopy, with temperatures registering at 76.4F consistently. I soaked 10 Greenhouse Seeds Co Indica Mix seeds in cups for about 5 hours (they sank within 5 minutes, literally all of them, so I was scared they might drown.) then straight to more cups with FoxFarm OceanForest, and placed under the light. 8/10 have sprouted, now three days later. One El Niño and one Trainwreck still haven't come up, and might not (the seeds looked a little small and crappy). I just don't understand what takes people so long to dial in settings, and there is an awful lot of hate for GHS that I feel maybe a little unfounded. I mean the colored-coating is stupid, and I probably got a couple of nummy seeds, but the rest are doing great. I guess I'll have to watch for hermies later on before I decide for sure.
Lmao, you've barely begun dude. Don't go thumbing your nose yet. Wait til the plants are bigger and RH becomes a factor too. If growing was as simple as you play it out to be, an oz wouldn't cost $350. And if your all dialed in one this ever so easy grow, AND green house having such stable genetics, why worry about herms? Lol And the color coating is their way of legally selling beans as souvenirs.
Supply and demand, and capitalist tendencies are what determine the price, not the difficulty of cultivation. Most of the marijuana sold in the U.S. is not cultivated under ideal conditions for medicinal sake, but rather grow in bulk with little concern to remove males or spend hundreds of dollars a plant on nutrients. And don't forget, cannabis exists on the planet because it grows, produces seeds, dies, scatters seeds, and grows some more, not because pot-Jesus comes and checks the PPMs and juices them up ensuring a perfect environment for their cultivation. Temperature, moisture levels of the soil, light, and adequate nutrition are what is required. Certainly there will be room to improve, and become a better grower, but I also don't doubt that I can have amazing quality cannabis off the first grow.