DrMota-TheFirst
New member
Just one quick ques.: What is optimal distance from tops for 8-bulb T5 with all lights in use during veg? ...and accordingly do decreasing distances slow growth and possibly have ill affects?
-
As of today ICMag has his own Discord server. In this Discord server you can chat, talk with eachother, listen to music, share stories and pictures...and much more. Join now and let's grow together! Join ICMag Discord here! More details in this thread here: here.
T5 Usage
- Thread starter DrMota-TheFirst
- Start date
If you do a search around this site using T5 or T-5 as the search topic you will find a few threads.
There is a difference of opinion among the T-5 growers as to the distance from plant to light. I have a 4 x 4 table covered with a canopy of 9 T-5 Lightsticks
and I keep them about 4-6 inches above the plants with no problem. Another user reports heat issues if he gets closer than 18 inches above his plants, but he appears to be in Arizona or somewhere hot and has cooling issues in his grow.
Increasing distance reuduces the amount of light available to the plant on an exponential basis (there is a chart that shows this that you will find if you check out the other T-5 threads.)
There is a difference of opinion among the T-5 growers as to the distance from plant to light. I have a 4 x 4 table covered with a canopy of 9 T-5 Lightsticks
and I keep them about 4-6 inches above the plants with no problem. Another user reports heat issues if he gets closer than 18 inches above his plants, but he appears to be in Arizona or somewhere hot and has cooling issues in his grow.
Increasing distance reuduces the amount of light available to the plant on an exponential basis (there is a chart that shows this that you will find if you check out the other T-5 threads.)
SweetIndica2
Member
For pretty much any light, you can do the heat test method. Stick your hand about level where the tops of the plants would be, raise the light until you can't feel the heat anymore, this allows you to get the light close but not too close that it will burn the plants. Somewhere around 4-8 inches would probably be optimum, Good Luck!
DrMota-TheFirst
New member
Thx for the quick replies...needed to settle a difference of opinion regarding the issue....thanks a lot
I have used a 6 bulb T5 since January for vegging. I keep mine approx 1-2" from top of plants..
I do have a small 6" fan blowing over the tops of the plants.
The only trouble I have is when I don't look at them for a few days, sometimes they will grow right up to the bulb. Which will burn the leaf tips. I just cut off the burnt leaf & move the T5 up a little.
One thing I have noticed. I be a newbie though so don't take this for GOSPEL.
If I keep the T5 say 8-10" from a plant it grows not only much taller trying to reach the light, the spacing in between node's is much further apart.
I do have a small 6" fan blowing over the tops of the plants.
The only trouble I have is when I don't look at them for a few days, sometimes they will grow right up to the bulb. Which will burn the leaf tips. I just cut off the burnt leaf & move the T5 up a little.
One thing I have noticed. I be a newbie though so don't take this for GOSPEL.
If I keep the T5 say 8-10" from a plant it grows not only much taller trying to reach the light, the spacing in between node's is much further apart.
man, i have an 8 bulb t5 in a 2'x4.5' closet and have to run only 4 of the tubes. my plants were dying on me and yellowing out pretty bad. average temps in the closet were 86 but got as high as 90 between central air cycles(the closet is a/c'd). the light was about 12" from the tops of the clones in their pots, no real heat on the back of my hand and i had plenty of circulation. eventually i just went with the inside 4 bulbs and raised the light to about 18" above the plants. OMG they took off, its been a jungle ever since.
btw i tested the light output with a lux meter and with only 4 of the tubes on at a distance of 18", there was just as much light registering as in my 20"x48" cab with a 400w mh in it at a distance of 26". i didnt get to test it against all 8 bulbs or equal distances due to fixed equipment but DO NOT doubt the t5's. the test didnt cover penetration either as i figure the 400w mh would penetrate way farther than the t5 but the t5's are great for vegging even if you only use half the bulbs. if you have height, start off with all 8 but imo,i would do it at about 24" or more and then work my way in day by day. gl
btw i tested the light output with a lux meter and with only 4 of the tubes on at a distance of 18", there was just as much light registering as in my 20"x48" cab with a 400w mh in it at a distance of 26". i didnt get to test it against all 8 bulbs or equal distances due to fixed equipment but DO NOT doubt the t5's. the test didnt cover penetration either as i figure the 400w mh would penetrate way farther than the t5 but the t5's are great for vegging even if you only use half the bulbs. if you have height, start off with all 8 but imo,i would do it at about 24" or more and then work my way in day by day. gl
DrMota-TheFirst
New member
Sunset- you're right about plants stretching for light that was really noticeable in the dark ages when I was using MH, but even keeping T5's at 18" + at times, the nodes have still stayed tighter than closer distances with MH. Leaves are greener, grow time faster, and clones in the back root faster. T5's are the shizz.
G
Guest
On the t-5's, go to radio shack, tell them you would like to buy 4 toggle switches rated for your ballast and switch on or off , in pairs, as you like. Use your imagination on mounting them and "don't touch" any bare hot wires. The sheet metal ballast/wiring cover is a good place to mount them.
One thing nice about the 6 or 8 tube units is that you have more power/light if you need it. And you will sooner than later.
2 inches is good, and yes, check daily because you will burn the leaves by contact.
Happy Growing and Peace
One thing nice about the 6 or 8 tube units is that you have more power/light if you need it. And you will sooner than later.
2 inches is good, and yes, check daily because you will burn the leaves by contact.
Happy Growing and Peace
Got one of those Satellite Lights in BOB and man it kicks the shit out of my 400 with that being said it's a floro man if it won't burn your hand I say let it EAT!
The tighter the better someone once said. I'm just not sure what he was talking about but in this case I'm gonna say node's.
Mr.Wags
The tighter the better someone once said. I'm just not sure what he was talking about but in this case I'm gonna say node's.
Mr.Wags
Last edited:
