Okay, so as a beginner indoor grower using a tent for the first time, I think I may have made a mistake thinking I could use t5 multi lamps for growing in at least a small 4’x2’ tent for awhile till the need for a larger tent arose due to plant size, don’t think it would be different for a larger tent I was gonna get anyway. My Eight light 48" t5 fixture overheated my tent on the first day and damaged several of my plants, went to 88-89 degrees. Then I tried various things, using my 4" exhaust fan setup, don’t think it was good enough powered. I then took some plexi glass plastic pieces and taped them together and wedged the sides on each long side of the light and draw air across the bulbs with air from the spare room past the bulbs into the vent and into the bathroom is where warm air goes(to be improved later). Couldn’t achieve more than 81 to 82 degrees, I suppose unless I had a air conditioner blowing on the tent and the air drawn in till next winter, doesn’t seem a good setup. So I turned one set of lights off and now only have four t5 48" bulbs going, a little closer to plants, but temperatures are 79 degrees, even when I installed a air booster to boost some air into one side of the enclosed bulbs so it can be sucked out on the other end by the vent connected to the other room exhaust fan, and actually it aint far to the exhaust fan, just under the wall through the adjoining heat vent, a couple feet.
I think in this sort of setup I should have gone with those ducted mh or hps hoods with 6" hoods and a six inch exhaust fan setup, unsure. I put two of my best plants into my marijuana hospital, unsure why others were not affected, which I name for my single t5 cloning/seedling lamp I have on a shelf place above a lower shelf and not installed with its frame. They will likely bounce back, only the big leaves were damaged, bad, and one had curling leaves, and they have new shoots coming all over the main shaft.
You need a really good extraction fan at the top of the tent, make sure it is a good “vortex” or “centrifugal” fan, not just a standard ducting fan. These are much better at pulling/pushing the air through ducting than a basic duct booster fan. Also look at the cubic foot per minute or cubic meter per minute rating and decide if that will remove the entire amount of air from your tent, find the total volume of your tent by its dimensions, do the simple math, height times width times length to know the total volume of your tent, and then you can figure out if it is pushing enough hot air out and pulling enough fresh cool air in fast enough to keep the temps down at the root zone. The canopy itself should be able to handle pretty warm temps as long as the humidity is high enough and the roots are getting enough moisture and staying cool enough. In most situations your temps wouldn’t be too much to worry about as long as the roots aren’t that hot. Root zone shouldn’t get much above 68F degrees to 73F in hydro, and maybe up to around 75-76 max with a ton of aeration, in soil it can get warmer, but the canopy should be fine at around up to your temps in most cases.
It sounds to me that aside from having an inadequate fan you are not able to add cool enough air into the tent. Perhaps invest in a small portable AC unit. I have one and it is great in the grow room. 
Oh, I am using a vortex style exhaust fan, the four inch size with four inch ducting, I just used my booster fan to help push even more air in across my enclosed t5 bulbs. Of course, just like I used to say months ago, it seems a lot easier to have a very large grow room than a small one, seemingly. Of course, another thing, I should try to get vented air drawn from under the home, which means a hole cut in my floor, for that, but I am unsure how other people are able to use t5 multi grow lights unless they are actually talking about using them in a large open grow space with plenty of very large vortex fans, and/or air conditioning. I guess what has thrown me off is I have used in the past some fluorescent bulbs, the older t8 style, for house plants, they didn’t seem to heat up a room at all, not especially in winter or cold weather.
ALSO, …Another thought, I think my 4"(four inch) vortex fan is too weak to suck out enough hot air(probably why six inch ducts on lights and six inch fans seem to be most popular), UNLESS the air going into the tent is super cooled, and I improved on the idea of a plexi glass enclosure of the t5 light assembly. The problem with four foot(4’) long t5 lamps, no matter how many bulbs, that the ends touch the ends of the grow tent that is four foot long(4’), cause I wanted to duct hot air on the ends but there is no room. Oh well, I’ll find a way to improve on a t5 light setup somehow enclosing and ducting in time, hopefully, in the mean time I may have to order me some replacement equipment. I am sort of perplexed why I can’t seem to get much use out of a 4" vortex fan setup, a lot of them get sold, I just thought it was okay for a small tent.
AND GOOD POINT ON THE INCOMING TEMPERATURE OF COOLING AIR, oh sure, I know I can go several routes, drawing air from the room as I do now with an air conditioner installed in that room, or also with air drawn from under the home, maybe switcheable depending on temperatures inside and outside, like in summer outside air may be too hot during some days of the summer.
IN OTHER EVENTS, TODAY I RECEIVED MY TWO TRIPPLE SETS OF PLANT PROTECTOR(ROOT PROTECTOR/ANTI MOLD/ANTI BUG, probably will be no time at all till my three triple sets of marijuana booster comes in, can’t wait, I risk the plants everytime I guess at using miracle grow fertilizer powder. I think in two weeks time I will be growing competently with the proper setup at least for awhile till I work out my outdoor shed growing area dimensions and preparations. For right now, I want, maybe three tents in one room, or at least two, cause I am monitoring/watching nearly every couple hours, and all cause of heat, which has got to be solved in the next few days, I mean, if I have to do something temporary while waiting for different equipment, I’ll take my kitchen portable air conditioner and install it in that room, or cut a hole in the floor in the closet/water tank room adjacent to get cool air from below.
4" vortex fan is plenty for a grow tent. Even a small room. The only difference is how l;ong you run it to refresh all the air in the space. What is the cfm of the fans you are using? I will show you a formula
Oh, that is interesting that you say a 4" vortex should be enough, at least for a small area, all is not lost if I shelve it for later since I bought it with a carbon filter for a relatively low price and can use it for even venting a curing room/tent later, or such, with that filter. I agree, but ya know, they don’t even make a ducted light hood in mh or hps for 4", and even in a small tent, maybe a small tent, 4’x2’ would have benefitted from a 250 watt mh lamp.
Well, right now I am running the 4" vortex by IPower twenty four hours per day, THAT IS 175 CFM, I am not doing an 18/6 schedule, especially considering till I figure out what to do about heat, the four t5 lamps likely aren’t enough light, really till I work out cooling for the other four lamps to be turned on or replacement with something else that is duct cooled. Ya know, I knee jerked this morning and ordered more equipment I couldn’t really afford, out of savings, at least for later use no matter what, I bought an enclosed hood for adding on my 600 watt hps, wanted to buy a mh bulb or two but my favorite company was out, then I ordered some six inch vortex fans on sale for $69 each.
But yeah, I am running the vortex fan as long as lights are going, the way I thought a person is supposed to do, besides, even four bulbs keep it warm at 79 degrees, I suppose cause I don’t have but room temperature air being drawn in. I want to make a plexi glass enclosure for the t5 light, but it is too long to have air drawn off the ends effectivel, so I’d have to do it on the ends on the sides, in theory. Right now, I pretty much wished I had bought a 400 watt 6" vented hood mh lamp setup for the beginnings in the small grow tent, but now my favorite company is out of stock.
Forgot to mention I have 90 cfm booster fans, and have one blowing air across one end of the semi enclosed t5 light, with vortex venting duct slipped in on the other open end, a totally bogus setup, been busy, haven’t been able to go buy some plexi glass to make a proper enclosure, just thinking bout setting the t5 setup aside for later in a larger area in my outdoor shed, really. Right now I don’t have but seven plants going, waiting to do clones to get to my legal medical license amount. And the funny thing is I want another beginner grow tent, like a 4’x4’ or ideally a 5’x5’ to go in that room with the other one, unfortunately that was my bedroom the last several years too, wished I hadn’t bought so many reference books and book cases and dvd/blue ray movies with shelves. Gonna have to make my grow area in my outdoor 10’x16’ shed whether I like it or not, at least for flowering, that is sure.
UPDATE,…AND I WISHED A PERSON COULD MODIFY PREVIOUS POSTS OR EDIT LATER, OTHERWISE I WOULDN’T BE MAKING THIS TO WORDY AND LONG. …ANYWAY, I AGAIN EXPERIMENTED IN THE COOLER EVENING TIME WITH CLOSING OFF THE ENDS of my expedient taped on and together plexi glass bulbs cover, as described above, I ADDED CLEAR BUBBLE WRAP ON THE ENDS AND AROUND THE INTAKE AND OUT TAKE DUCTING and turned on all eight bulbs, and temperature is averaging out at 79 degrees with the light assembly raised maybe six more inches making for about two feet above or a little more above tops of plants, pretty much same as four bulbs previous in that temperature range. This proves a point, in a thrown together expedient manner that I can improved on this design, make sure cool air is intake, and have basically 8 t5 lights going in a very small grow tent, 54wx8=432watts total, and very bright. I am unsure if four t5 bulbs are enough, maybe they are, maybe they aren’t, maybe 8 t5 bulbs going is way way better for excellerated growth. I’ll have to make sure I don’t go above 79 or 80 degrees during daytime, till I work out cool or cooled air being drawn through the t5 light bulb assembly. Hopefully I aint overheating my t5 light assembly and potentially damaging it, I will monitor that possibility as well. Maybe I am one of the few knuckleheads who ever tried to put a massive t5 light assembly in a small grow tent instead of just going tradition ducted cooling mh lights, go figure, I always strive to be different.
Of course, right now electricity useage costs is important cause I only have five larger plants and two younger ones with their first leaves and thin stems, later if I have a bunch in vegging, 18 non flowering of various sizes, and six flowering drawing a lot of juice/money it will be more worth it, but I aint up to the point of being able to cut some clones to increase my numbers. Still I wonder if later using a six inch ducting and exhaust fan and six inch booster fans would be better, I’ll figure it out maybe.
If we were all the same there wouldn’t be anything to talk about thus no forum…lol
It’s always good to be different my friend.
Here I have 27 ladies growing in a grow tent that’s 97x97x6’ under two 400w hps that hang 3’ from the girls. The first pic are my clones taken from mothers that were 4 wks into flower it’s called monster cropping and the 2nd pic are the 20 free seeds of W.W
Will 
Really, I didn’t think I would post another “update”, so this is for all other beginners out there researching out problems or what to buy or use or what to look for when or if they use t5’s, but I just want to say I have a semi cool home in the evening/early morning hours, and with 8 lamps going, the temps raised to 84 degrees even with a large fan blowing air over the tent intake/into room, just had to switch to four bulbs till I fix this problem. The problem is I need outside cool air, maybe from under the home brought in, or I need the portable air conditioner in the spare bedroom window cooling that room, I’d say, keeping the temperatures at 65 to 70 degrees to be heated when drawn in the tent could stay about 75 to 80 degrees.
I’m only posting this to help anyone else make a decision or having similar problems of what light to use/buy, I mean, if you have cool air being drawn in, very cool air that is, maybe with an air conditioner, hey, no problem likely then. Plus the fact I am dumping the warm air in the bathroom next door to the room and just keeping its door closed, the warmish air generally escapes out the bathroom fan duct without running the bathroom fan, errrrr, seemingly. If I didn’t have some chronic health issues bugging me, a broke down truck, and a bunch of pulled tendons in my left shoulder making me pray to god my medical marijuana card comes soon, I’d just be doing this all out in the outdoor shed and leaving the window open if things got hot without working out proper cooling first, unfortunately I have less electricity out there.
I’ll obviously use six inch ducted exhaust vortex fan when my two come in, maybe have to move the air conditioner in that room, improve the t5 light fixture or get a mh 600 watt bulb and use the new duted cool tube xl for cooling, even if I have to get a larger tent for vegging, so help me god. Ya know, I have my bed in the room with that stuff, the fans, etc, and the extra noise actually helps me sleep, and I feel the smell of marijuana plants growing is soothing somehow for me, or at least my sinuses, they haven’t flared up since I started growing in my bedroom/library.
Hey budbd. Sorry to see your having problems with heat issues with your tent. I personally think an mh bulb might be a bad idea as those things even enclosed with air drawn across them still create a lot of heat. I had an idea with mine. That worked pretty well when I tried it. I have a 2.5 sq. x 5ft tent so it’s about the same sq. footage as yours. And I was using 2 150 watt hps’s. I bought a 7in Honeywell fan and put it next to one of my intake holes on the floor pointing straight up at the lights and that really helped bring the temp down at the canopy. With a 4 ft long tent I would buy 2 and one at either end. Get a fan you can point straight up. Their cheap and can be used elsewhere when needed. Just my thoughts. As an aside, I purchased a P300 LED light and am going to get another. I will never go back to hps. No heat issues and my electric bill is less. Not by much of course cause it’s not much in the way of power usage but every little bit helps. Anyway I hope this can help. Good luck
So mikea, you are using some sort of led light, that says it is 300 watt(or actually uses 300 watts?)? Ya see, months ago, I spent loads of time reading and thinking I would have been better off starting right off with led lights, …less electricity, and likely less heat, I could have cared less if I spent $300-$500 for a light or $600-$700 for two together. I mean, I of course, take it to heart you are right about too much heat from even a 600 watt mh in my small tent, or even likely in my opinion in a slightly larger tent like a 5’x5’, but eh, a person never really knows till they try, and ummm blow hundreds of dollars for equipment that aint exactly the right stuff.
I believe the problems are “tents” as opposed to wide open spaces. I think if I gave up the idea of using any tent past a single t5 bulb for propogating cutting/clones and seedlings inside a small tent, and just installed a table with plants on them in the same corner with a “hot lamp” above it, likely ducted to the bathroom six inch fan, and a small air conditioner in the room with thermostat set to 70 degreees, I’d probably be a person wondering why other folks have heat problems when growing is such a no brainer. I could likely even use the mult t5 light, ducted still, with air conditioner and thinking growing pot is a no brainer indoors. Tents,…yeah,…very difficult with them!
I think I might try to again figure out this whole led light thing, I could always experiment with a few plants later while my others get traditional light sources.
Man, I just ordered me a 600 watt IPower led light fixture, hopefully the picture was correct that it looks like two 300 waters that could mean two switches, don’t care really. I paid bout $200, I’ll experiment with it, and of course still use hps for flowering later. I like Ipower brand, was unsure bout whether or not needing a different brand, or etc. I mean, as long as it can simply veg plants, I decide next year if leds can do flowering, errrr, after I put some serious use to my hps fixture. My massive fluorescent, well, I can think of all sorts of light fill in or uses. I wouldn’t doubt I go 100% led even this year, I could take a few clones and study flowering with them in the small tent when I use a larger tent or move out in my shed for growing.
So, by next Friday I will be using a 600 watt led light instead, for heat reduction.
Budbd, yeah I do like my led light, but like you I’m using a t5 light though. Mine is 2ft 4 bulb for seedlings right now. Just 2 Gold Leaf. Sounds like you’ve gotter figured out so I genuinely hope the mh fixture works. I’ll be watching your progress hoping for some massive buds for ya. Good luck man.
Yeah, mikea, I just wanted to point out I don’t have any mh 600 watt bulbs, I found out last night I could have ordered a couple, but I’m thinking I may never have to use a mh type light setup now, plus those bulbs are like almost $28 each, and the money I’ve blown on “vegging” alone already too much. I read from the seller of these ipower led lights that plants soak up more led emitted light than traditional mh or hps, …I wonder if that is exactly true, I mean, who knows. I consider ordering some mh bulbs for my 600 watt ipower dimmable light setup, maybe, as a backup or a double bulb style/fixture for massive budding by purchasing a second fixture setup(I saw a video where mh and hps lights were set close together for premium budding, eh, what do I really know at this point)I’m pent up about “vegging”, after all, my current plants are behind schedule in growth cause I kept them under a single t5 48" bulb for a month, not enough light.
Hey budbd. Just wanted to comment on your mention of LED vs hps or mh fixtures. I couldn’t agree with you more on that fact. Who knows? If they would just legalize it like IT SHOULD BE, then there could be scientific studies to determine just what is what. But that’s a whole other can of worms for another topic and thread. But the side by side studies done by laymen on YouTube and other forums seem inconclusive at best. Some say leds others hps. I subscribe to a site on YouTube called Monster Gardens and their conclusions are, and these are by no means scientific, hps is for quantity and LEDs are for quality. As for the girls soaking up more LED light than hps, I’ve heard that. But more for the fact hps’s have more wasted energy in the heat they create. LEDs lights are more focused. True or not? No clue. I know hps’s put out some great yeilds and great bud. This will be my first real grow with LEDs as I bought my light with only a couple of weeks left from my last grow. Can’t wait, very excited. Damn, I just looked back on this and it seems I’m writing a book here so I’ll quit boring you. Take care budbd.
Hey budbd ,god I wish I could let you into my brain for 2 minutes but then you might take over the world. lol you’re making this so hard on yourself when it’s really the process is so simple work smart not hard then pay attention to your plants and you will be super super happy but you have plenty of light as long as your lights are new bulbs .bulbs tend to lose their frequency wave overtime so make sure to mark your bulbs so that way you remember how old they are and from there I learn how to water really well make sure you don’t over water and make sure the plants have nutrients but you’re not feeding them you’re just making sure they’re happy and have everything they need too many people think they need to feed them when feeding is’nt what they need just care but not too much hope you get this s*** figured out much … love… peace
Oh, thanks peach fuzz, that is interesting bout frequency of bulbs going getting weak over time, I hadn’t thought of it, though, everything I own is like brand new and haven’t started using the hps I own. Well, yeah, I am like practically writing a book myself mikea on simple pot grow, and I like that idea that leds are maybe for “quality” and not “quantity”, though I could sure do with some quantity in the very beginning. And of course, I am stretched to the limit financially on any more equipment for awhile, I may buy a 4’x4’ tent for indoor in several weeks, another hundred bucks, only cause I want to be monitoring my first grow regularly throughout the day without the journey to my outdoor shed that will eventually be set up for the small personal grow. I think during winter, during the coldest months, I will grow my medicine indoors and share the heat throughout the home, summer out in the shed. I could always clean out the one room entirely of bed and possessions, no tents, but hanging hot grow lights, vented out a carbon filter out of the vent over the door frame to warm up the rest of the home, so heat can be a good thing, saving money in winter, ha, maybe that will be when I am growing with mh and hps lamps four months out of the year.
LEDs are good for both quality and quantity, but you have to know how to use them. They can be much better and possibly save you even on a lot of heat compared to High Output T5s. You obviously did over do it for the size of the tent you have. The difference between T5s and HID’s is you can get away with using less watts because you can get the lights a lot closer to the canopy of leaves, thereby giving you the same lumens or foot candles at the leaf because light intensity dramatically increases or decreases depending on distance due to the inverse square law of radiation.
It isn’t so much the frequency that changes, but yes the intensity of both fluorescent lights and HID lights like metal halide or high pressure sodium will decrease over time before the light burns out. Many people change their HID lights every harvest even if they haven’t burnt out due to this.
LEDs do not experience this same dramatic drop off of intensity over time and LEDs can put out the same amount of effective PAR, relative to the equivalent lumens as a HID and save over 30% of electricity usage and save at least as much if not quite a bit more on the heat as well.
Here is a link that might help you understand the difference bwteeen various lights better. http://www.htgsupply.com/faqs