The T5 thread

303

303

Well-Known Member
I love my T5, much more efficient than the ol' metal halide. Would never consider flowering with this light though... Here's mine...
 
volcanoOFhistory

volcanoOFhistory

Well-Known Member
infinitescrog said:
I have twin 150 Watt T5HO 4' strips each with 1 10k and 1 actinic and they get pretty hot but they work great for me to veg...plants exploded under them with very little stretch.
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Those are probaly not t5s but are compact fluro's. The compact's get a lot hotter than the t5's
 
S

scoobiedoo

Active Member
I am a newbie and just started growing under lights last year. I bought two 2'x4' 6 bulb T5HO fixtures and, i think, each bulb requires 54 watts. I grew plants from seed and was burning seedlings when the fixtures were inches from the plants. I had been accostomed to starting plants indoors with T12 bulbs and they had to be right up close to seedlings. As the plants matured i wound up settling on keeping the T5 fixtures about 15" from the top of the tallest plants. If leaves browned up i assumed it was because i had the fixtures too close to the plant but you say they can be only a couple of inches from the plant.

I will read my books to see what the difference between SOG and SCROG are. What you had looked beautiful and i would love to imitate it. But I would like to get legal now and in Vermont, with medical marijuana, you can only have 7 immature and 2 mature plants. What you had (in another post) looked like many small clones. I was planning on trying to stay reasonably legal and start 7 or 8 seeds and keep whatever females i identified at around 3 months and then switch to flowering. I have done it for two years now with t5's and had mixed successes with plants that reached to about 4' from bottom of pots - always keeping the fixtures 12" to 15" above the tallest plant. Could the browning of leaves at the top be more the result of poor circulation, heat or other deficiency than from having the fixtures too close to the canopy?

i just put up a post in the "grow room design" forum asking for ventilation assistance descibing what I am trying to do. I would appreciate any suggestions you are willing to offer.

Thanks......
 
ataxia

ataxia

Well-Known Member
303 said:
Benefits from flowering with T5?? With all do respect I don't see any other than heat. Its like poor man flowering...
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while it may not be the same exact penetration as an HID.... The benefits are the same ( better imo) than cfls. I MUST POST A PIC. lights come on in an hour. I'm about a week from harvest and if i didn't tell you it was a T5 for flowering you wouldn't know the difference,
Love those pots also 303. what size are you using .. i have 7 inch, and 10 inch.. I can't find any specs on volume size of these pots
 
M

m0t0keS

Active Member
flowering with a t5 has its advantages but then again your not gonna get enough light penetration like you would from say a 400 watter,t5 can be alot closer to the plants and be able to handle it with ease
 
M

ManicOrganic86

Member
I run 3 t58bulb 434watt guys for flower. Im getting about 105 grams a plant on a 1 1/2month veg using cutting edge line and sunshine 4. 3 gallon deep pots to save space. lots of tying down at the start of flower to max canopy. If you need some picks ill try and find some. I went through 7 strains before finding ones that work well with t5. the heat save is great. and the power save.
 
G

gobbly

Well-Known Member
I think it was touched on once, but don't neglect the difference in growing styles. HID penetrate better than T5's. This is unquestionable, it's simply the physics of having X number of watts coming from a few cm^3 opposed to X number of watts coming from 1000cm^3 (these numbers are made up :D). To flower with T5's you have to grow completely differently. You want short bushy plants that spread out under the light instead of going up. Think scrog, sog, or severe lst/pruning. As long as you can keep the light penetrating well, and have enough tubes with good reflectors, t5's can match HID output. It just takes manipulation to maintain the proper distance to compensate for the lack of penetration.

On temperature, I find a lot of people don't really understand light and heat. Watt for watt HID and flo put out the same heat. As I mentioned earlier T5's run at a PF around .5-.65 (50-65%), HID run at a PF of around .98-1 (98-100%), so you have to adjust wattages to what is actually being drawn by the devices. With that in mind though, a watt between the two is a watt, and both will produce roughly the same heat per watt. The caveat to this, and the reason most people say they are cooler, is that the heat produced by a T5 is spread over the entire surface area of the bulb, and thus is more evenly dissipated. The heat from an HID is all produced in a very small area, and as such is a much more concentrated heat. T5's still get hot. If I get my plants closer than 2" or so from the bulbs they start to wilt, same if I get them closer than 4" and don't have an oscillating fan blowing across the bulbs. If I didn't have ventilation, the total heat in my closet would be the same between the HID or T5's assuming I matched wattages.
 
Total Head

Total Head

Well-Known Member
scoobiedoo said:
I am a newbie and just started growing under lights last year. I bought two 2'x4' 6 bulb T5HO fixtures and, i think, each bulb requires 54 watts. I grew plants from seed and was burning seedlings when the fixtures were inches from the plants. I had been accostomed to starting plants indoors with T12 bulbs and they had to be right up close to seedlings. As the plants matured i wound up settling on keeping the T5 fixtures about 15" from the top of the tallest plants. If leaves browned up i assumed it was because i had the fixtures too close to the plant but you say they can be only a couple of inches from the plant.

I will read my books to see what the difference between SOG and SCROG are. What you had looked beautiful and i would love to imitate it. But I would like to get legal now and in Vermont, with medical marijuana, you can only have 7 immature and 2 mature plants. What you had (in another post) looked like many small clones. I was planning on trying to stay reasonably legal and start 7 or 8 seeds and keep whatever females i identified at around 3 months and then switch to flowering. I have done it for two years now with t5's and had mixed successes with plants that reached to about 4' from bottom of pots - always keeping the fixtures 12" to 15" above the tallest plant. Could the browning of leaves at the top be more the result of poor circulation, heat or other deficiency than from having the fixtures too close to the canopy?

i just put up a post in the "grow room design" forum asking for ventilation assistance descibing what I am trying to do. I would appreciate any suggestions you are willing to offer.

Thanks......
Click to expand...

there is absolutely no reason whatsoever to have t5 lights 15'' from the canopy. hell i don't even keep my 400w hps that far. if they were burning seedlings it may have just been too much heat for such young plants but a fan should clear that up no problem. when using t5 i always keep them within an inch or two of the canopy. i would move them closer if not for the fact that they have to be raised daily as it is. in a sog or scrog setup the canopy is much more even and this enables you to keep the fixture close to all the plants but those techniques work better with clones than seeds. i'm not sure what you mean by "reached to 4' from bottom of pots". do you mean they were 4 feet tall? i am assuming your plants were stretched beyond belief with floro light that far, and the browning of leaves could have been from a number of things but lack of light definately had a hand in it. floro light is only efficiant when it's kept as close as possible, which is pretty close.
 
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