Hey guys, my rooted clones were having trouble in perlite but have been in soil for a couple days now and aren’t drooping anymore! The air cooled 600w MH is about 3 ft above the leaves, the humidifier has the humidity between 70-80%, and the temp is sitting at 82F steady. Are these good conditions? I want the temperature closer to 75 but i can’t seem to get it lower than 82… Side note, in the picture the humidity is reading lower because the tent had been open for a couple minutes before I snapped the picture, but when closed it sits between 70-80%
I believe that you will be fine. MJ plants are so adaptive. As long as you keep variables consistent, you can grow in that environment. After you see the clones growing, I would get that humidity down into the 50% range for vegging, and below that into the 40% range in flower
Looks like I will have to buy yet one more gadget for growing, a humidifier, been growing in a tent for three days now, and apart from temperatures about 84-85 degrees, there isn’t much humidity at all, tried to putting water in a container, but no dissipation. Of course, my heat problems are from eight t5 48" lights on, producing all that heat, at first I had 88 degree heat, but I opened a bottom flap to have air drawn across the plants, cause my exhaust fan is on the bottom of the tent, gonna have to get me longer ducting and draw hot air out of the top of the tent. Makes me wonder bout your setup air cooled mh or hps light, I almost think it would have been better to just go with that setup, maybe I’d be running cooler. Or maybe my problem or anyone elses is too high wattage light source for small grow areas, beginning to think tents are good for very low wattage lights, like 250 watt lights or like maybe four t5 lights instead of eight going all at once. Which comes to my original point a over a month ago when I was researching, bout whether or not led lights were the way to go, beginning to think so, but folks say they require a “learning curve”. Hopefully my learning curve won’t be damaged plants, a expensive eight light t5 light set off to the side for later uses and having to just buy a led light setup or two anyway, errr, for tent use. Actually, to use a cooled light tube, I’d have to go with six inche exhaust fan instead of the four inch I have, meaning I’d have to buy a six inch exhause fan setup then a air cooled hood.
You just have to deal with removing the heat from the enclosed growing space, no matter the light. A good high output LED can still create a lot of heat, especially an LED system that that will preform as well as or better than a 8 x 4 ft T5 light. People run 600 watt - 1000 watt HPS in 4 foot by 4 foot tents that are only about 6 or 7 feet tall. Most would use a 6" air cooled hood in a tent like that, In fact dealing with getting rid of the heat might be easier with HID lights as there is not really “enclosed air cooled hoods” designed for T5s or LEDs.
This is great info MacG. So; We can acknowledge that even when using LED lamps; We must prepare for exhausting heat from our grow space. This is a n important piece of info for growers deciding on which lamps to use. Thank You!
Yeah high power LEDs don’t get as hot as HIDs, but they will get to almost as hot as a equivalent high power T5 light like the 8 tube system previously described.
Well, I damaged two of my plants from “heat” from what I can tell, the other three that were in my tent didn’t seem to get damaged, having started using the tent for the first time five days ago. I know I had temps initially that climbed to 88 degrees, saw a 89 before I took action many days ago, using 8 t5 4’ lamps of course. One plant had several lower leaves curl in the “too much heat” way, the other plant the leaves on the lower area, big leaves on my best plant were still green but dry and crack half way from the tips. I have a exhaust fan near the surface of the t5 light assembly thus cooling it further and the lower flaps open, dropped temperatures to 84 degrees, now I noticed I can leave the door slightly unzipped till I take further action to remedy my problem with heat cause I noticed a 79 degree temperature then. I removed the damaged fan leaves and dipped their stems in rooting compound and installed in peat plugs hoping to get some clones in time, unsure if this method will work for cloning when I have done this with other style plants before, worth a shot at least.
So, my next move it using the extra long four inch ducting and taking air from the top of the tent, with the duct down next to the hanging light to removed heat from there. At least the plant with the removed damaged fan leaves has shoots coming all over the stem shaft. I also worried about overwatering, I was not well for the last several days, and I poured distilled water and not fertilizer on the plants, but checked them twelve hours later to see they were sitting in water in the water pans, not good of course, removed from the water and put on small saucers till the water evaporates, so I aerated the soil on all the plants especially with problems just in case of overwatering as well, with a butter knife, so they dry faster, cause I know I had a slight tendency to make sure the soil didn’t get dry at all.
Hopefully this will help out anyone else, I have my t5 light assembly about two feet above the plants right now, I may have had the light assembly too close to the plants initially, with all that heat, probably why the two best largest plants I have show the damage, they were taller, but hey, they aren’t dead.
Speaking of cooling a t5 multi bulb lamp fixture, with air, I got some sort of idea of getting a large piece of plexi glass and make some sort setup with four inch duct opening to draw off hot air, only cause I feel t5’s would be great for vegging with lower power useage in small spaces, but beginning to think I could be wrong somehow. Strange how the heat is at the bulb area, not on top of the fixture. AND I DON’T have a humidifier going, was sort of thinking I could get away without one, the best one I saw was a 24 hour capacity and was like $70.
Go to Walmart. I got my humidifier for less than $40. It’s cold vapor, doesn’t need filter changes, and has 24 hour capacity
You said you have your exhaust ducting down close to the light assembly to cool in that area. Since heat rises, if you want to take out more heat then raise your ducting close to the top of your tent. That is where the heat will go to very quickly
I am back to using the aforementioned 8 bulb light bixture in my newer emplaced 4x8 foot tent that has six inch ducting in and out(two six inch vortex fans). The 6 inch vortex for extraction is put inside the end of the home made plexi glass cover, and wow, what power of air sucking power, I had initially used a empty aluminum pop can to prop up the other end to keep it open, but the fan suck it up to the opposite end of the fixture and up into the ducting to the end of the vortex fan, scare the heck out of me thinking I just ruined a expensive fan, but turns out the hub of the fan didn’t allow it to get chewed up, do I taped a piece of ducting on the other end but didn’t enclose around it, wouldn’t have happened, the collapsing if I had a one piece of plexi glass instead of a bunch taped together(to be rectified soon with one piece thin flexible type). I sometimes almost wonder if I really need a six inch fan blowing air in other than for cooler outside air, except for the night times that get maybe too cold, and will have to put the intake fresh air on a timer to shut off during the coolest times. I mean, I have health issues that have slowed me down considerably, so I hadn’t started using it again till like a week and a half ago. I could probably use it without a ducted hood taped to the fixture, with the proper cooling I have going on, will see, but a bowed piece of plexi glass can’t be a totally bad idea to keep heat away from the tops of the plants, and like I said, could be a energy saver by reducing heat, I might not have to use a six inch vortex fan maybe, just run a open duct to inside of shed, for the vegging room only of course, with t5’s. I have two additional t5 cloing single four foot lamps hanging for smaller plants, so a total of ten t5’s are going on in that tent.
The vortex intake fresh air fan, six incher is blowing so much wind, I haven’t installed a set of small fans yet, I mean, air is circulating, a lot. I’m probably wasting electricity somehow, I mean, each six inch vortex fan uses I believe 150 watts, will check if I am right.
***UPDATE, IN MY ONGOING POSTS OF “DON’T LET THIS HAPPEN TO YOU”, hehe, like I was outside repotting my plants and I am convinced I should commence flowering in at least two weeks of bout four of my largest plants, I’d do it right now if I could for those, but just being repotted, dunno, the longer I feed them the new organics the better I will be in the long run for decent bud quality once cured, two of them I labelled months ago as “prime example” and the other two marked “never damaged much”, I mean, they are super big, properly proportioned, and I am running out of room, lest I try to erect another large tent in my grow shed, a third 4x8, well, actually can’t afford one. Likely, I will have to grow some minor smaller plants I have in another tent in my small 2x4 foot grown tent in the house, where I can just use two four foot 75 cloning lamps, as long as there aint a lot in there and they are smallish, because I let things go too long in that tent. Or I put that tent in the shed. I mean, I don’t currently have the upper limit of plants for my license as stated above, just that all I do have in clones are getting large themselves and these super large ones, wished I had a big discreet back yard, but my area is rife with bugs, plant diseases, super high winds sometimes from the ocean two to three miles away, being on the coast, a constant struggle outside when growing various other plants outside, apart from a sudden mole mound explsion(they probably smell pot and wanna eat it, around my shed, strangely, I wonder if its true they sense plants in there, I mean, I thought they went after worms and such in the soil. .
Wow, that is a lot. It is hard to follow.
I usually have the most powerful centrifugal or “vortex” fan expelling the hot air at the top of my tent, creating maybe a slight lower pressure inside the tent than outside. This usually is pulled through a carbon filter hanging in the top of the tent, and then through the fan and out the tent. This helps keep the tent smell proof, as well as exhausting hot air out of the top of the tent.
You had to create a hood to try and vent the hot air out and way from your T5 light housing, if I remember correctly?