that bear smokey
Well-Known Member
I am thinking of trying T5s for the 1st time in a 32x32x60 grow tent. what type of ventilation would I need? and what are your thoughts on using T5s? any comments would be great, any pictures would be great too.
any pros and cons, maybe your thoughts of using T5s.
- Thread starter that bear smokey
- Start date
I was skeptical but I saw first hand an inexperienced grower take some short plants about 16 inches tall and yield 1.5 oz per plant total of 3 plants with like 1 week veg time. The bud was dense and the smoke was great and the leaves stayed green perfect untill harvest.
set up was
-a coat closet 3x6 ??? maybe
-soil (empire builder)
-4' x 4 bulb - T5 with switched spectrums for veg and flowering
-a basic fan
-MG fertilizer (gross i know)
seems the trick is short plants as the t5 only penetrates about 8 inches but per watt I believe T5 can rival HID lights...I wont take a risk of not using my 3000w setup tho.
set up was
-a coat closet 3x6 ??? maybe
-soil (empire builder)
-4' x 4 bulb - T5 with switched spectrums for veg and flowering
-a basic fan
-MG fertilizer (gross i know)
seems the trick is short plants as the t5 only penetrates about 8 inches but per watt I believe T5 can rival HID lights...I wont take a risk of not using my 3000w setup tho.
that bear smokey
Well-Known Member
ok thank you.
T5's lumens/watt efficiacy is as good or better than most MH lamps (see the Wikipedia article on "luminous efficacy" for basic information). Regular T12/T8 bulbs are nearly as efficacious and far less expensive, so I'd use those. Straight 4' fluorescent tubes produce more light from their centers than their ends. They make excellent vertical side lighting in small spaces (such as your tent). They worked great in my second indoor grow...
If I were setting up your tent, I'd use 4 two-bulb 4' "shop lite" fixtures mounted at root level (the bottom of the light mounted slightly above the top of the container) and a 12" circular bulb (or larger if you can find one with a screw-in holder/ballast) in a clamp light (minus the clamp and reflector). The 12" bulb is suspended by the power cable (the power cable is stronger than a "light yo-yo" so don't worry about it) and "follows" the plants upward as they grow. You could also use 24" tubes (4~6 bulbs ought to work OK). T12 tubes can, in my experience, penetrate 18" pretty easily so my recommended lighting setup should give "full coverage" in your tent (as long as there's top lighting as well). Change the bulb types according to vegetative (cool white) and flowering (warm white); just normal fluorescent tubes. They're a lot cheaper and their luminous efficacy is nearly the same as T5. Consider an air-cooled 250W HPS in place of the fluorescent top lighting during flowering for a little more intensity.
As far as ventilation goes, it really depends on whether the room the tent's in is climate controlled or not (and what the climate is like where you live). The tent, being just 32 cubic feet, doesn't require much of a fan to keep the air "fresh". 12 CFM exhaust (don't waste money on a powered intake) would almost be overkill if the tent sits in a climate-controlled (heated and air conditioned) room. Obviously, you'll want to get a small (4") matched fan/filter combo and a good speed control. You'll also want one or two 5"~7" oscillating clip-on fans to circulate air inside the tent (and simulate the wind). The oscillating fans will strengthen the plants and help stabilize the temperature inside the tent.
If the room isn't climate controlled, then things get more complex/expensive because you'll need to control the tent environment more aggressively (heating/cooling/humidity). A dehumidifier is likely to be necessary to prevent "bud rot" and powdery mildew during flowering. If the dehumidifier is "powerful" enough, it can even be used after harvest to turn the tent into a humidity-controlled "drying/curing room". It can also be turned into a hydroponics reservoir chiller (there's a thread on RIU somewhere; the build was done for about 1/3~1/2 the cost of a commercial chiller - quite impressive). OK; now I'm just rambling. Good growing!
If I were setting up your tent, I'd use 4 two-bulb 4' "shop lite" fixtures mounted at root level (the bottom of the light mounted slightly above the top of the container) and a 12" circular bulb (or larger if you can find one with a screw-in holder/ballast) in a clamp light (minus the clamp and reflector). The 12" bulb is suspended by the power cable (the power cable is stronger than a "light yo-yo" so don't worry about it) and "follows" the plants upward as they grow. You could also use 24" tubes (4~6 bulbs ought to work OK). T12 tubes can, in my experience, penetrate 18" pretty easily so my recommended lighting setup should give "full coverage" in your tent (as long as there's top lighting as well). Change the bulb types according to vegetative (cool white) and flowering (warm white); just normal fluorescent tubes. They're a lot cheaper and their luminous efficacy is nearly the same as T5. Consider an air-cooled 250W HPS in place of the fluorescent top lighting during flowering for a little more intensity.
As far as ventilation goes, it really depends on whether the room the tent's in is climate controlled or not (and what the climate is like where you live). The tent, being just 32 cubic feet, doesn't require much of a fan to keep the air "fresh". 12 CFM exhaust (don't waste money on a powered intake) would almost be overkill if the tent sits in a climate-controlled (heated and air conditioned) room. Obviously, you'll want to get a small (4") matched fan/filter combo and a good speed control. You'll also want one or two 5"~7" oscillating clip-on fans to circulate air inside the tent (and simulate the wind). The oscillating fans will strengthen the plants and help stabilize the temperature inside the tent.
If the room isn't climate controlled, then things get more complex/expensive because you'll need to control the tent environment more aggressively (heating/cooling/humidity). A dehumidifier is likely to be necessary to prevent "bud rot" and powdery mildew during flowering. If the dehumidifier is "powerful" enough, it can even be used after harvest to turn the tent into a humidity-controlled "drying/curing room". It can also be turned into a hydroponics reservoir chiller (there's a thread on RIU somewhere; the build was done for about 1/3~1/2 the cost of a commercial chiller - quite impressive). OK; now I'm just rambling. Good growing!
that bear smokey
Well-Known Member
wow thank you. that was very helpful.
I forgot to mention that you'll want to get the exhaust air from the tent as far away from the intake as possible (preferably out of the structure). Otherwise, you'll just be recirculating the same air back into the tent when it's picked up by the passive intake. Unless you're providing the CO2 the plants need, they will need fresh air. Modern construction methods aren't exactly known for allowing fresh air into a structure (they're made to be nearly airtight). If you live in an old drafty house, getting fresh air to the plants won't be as much of a problem.
If you choose to add an HPS light during flowering, you'll probably want an air-cooled hood/tube. The HPS will add a significant (at least in that space) amount of heat and it will need to be dealt with. The exhaust from this duct run, too, should leave the area (or you can use it to heat the room in winter). I don't think I'd use much more than 250W in that small tent.
If you choose to add an HPS light during flowering, you'll probably want an air-cooled hood/tube. The HPS will add a significant (at least in that space) amount of heat and it will need to be dealt with. The exhaust from this duct run, too, should leave the area (or you can use it to heat the room in winter). I don't think I'd use much more than 250W in that small tent.