Led Users Unite!

matticusn

New Member
So, my father gave me a grand idea. We have a detached "workshop" out in the back yard which is about 10' by 14' -- I can probably get 2 layers of plants on both sides of the workshop if I make them about 3 1/2 ft by 10 ft. That will give me 140 sq ft to work with, or 2,000 plants.

I know this is the LED forum, but how much energy would I use and how much heat would I generate using eight 4-foot-long 6 bulb T5s? I figure two fixtures on each level -- 4 levels -- 8 fixtures total. I'll start with 1 fixture and probably go up by 1 or 2 at a time per each 6-week grow cycle.

Using that much energy, would LEDs be a better way to go? Ceiling is probably 7 feet high, so each layer would be about 3 feet tall, and the total height of the plants would not be higher than 1 foot, pot included.

Any of you guys know of what A/C unit I would need to keep the place close to 72-74F in Florida?
 

ReefBongwell

Well-Known Member
2,000 plants? don't think so.... sounds like a quick route to federal pound me in the ass prison ;) especially in florida. get a good a/c it's f'in hot there :) Is there a reason you're trying to do a ton of small plants instead of fewer bigger ones?? bigger plants will put out more bud.
 

matticusn

New Member
2,000 plants? don't think so.... sounds like a quick route to federal pound me in the ass prison ;) especially in florida. get a good a/c it's f'in hot there :) Is there a reason you're trying to do a ton of small plants instead of fewer bigger ones?? bigger plants will put out more bud.
I'll be growing bio-lumenescent arabidopsis, not cannabis.
 

SnotBoogie

Well-Known Member
To cover that amount of space with LED is going to cost a fortune, the main reason using high quality LED is viable for cannabis is the artificial inflation of value due to its' illegal status. This could be alleviated if you DIY'd as i suggested before, but you dont seem interested in that.

We cant really tell you how much heat is going to be put out, unless you want an answer like "quite a lot".

For a more specific answer, i.e in Watts, a good rule of thumb would be to assume that your lights are 20% efficient, i.e 80% of their wattage = heat. Sooooo 100 watt light = 80 watts of heat.
 

Youknowwhoiam

Active Member
Hello all, you`d normally find me in here https://www.rollitup.org/indoor-growing/416589-12-12-seed-thread-264.html Iv`e only just found this and have only skimmed through a few pages so I thought I`d chuck up a few pics of my set up and current situ..


Secret Jardin DS60 MK2
2x Prakasa 90w 5 Spec UFOs
6" RVK pulling through a 6" CF
5L pots, Bio-Bizz Light Mix with Bloom and Grow nutes.

Iv`e been using the leds a few years now, I used 125w cfls before and wont switch back as I`m more than happy,

Here`s a few pics taken today, click the above link for more photos smoke reports and updates.




 

matticusn

New Member
To cover that amount of space with LED is going to cost a fortune, the main reason using high quality LED is viable for cannabis is the artificial inflation of value due to its' illegal status. This could be alleviated if you DIY'd as i suggested before, but you dont seem interested in that.

We cant really tell you how much heat is going to be put out, unless you want an answer like "quite a lot".

For a more specific answer, i.e in Watts, a good rule of thumb would be to assume that your lights are 20% efficient, i.e 80% of their wattage = heat. Sooooo 100 watt light = 80 watts of heat.
I think my only option then would be to run LEDs, if T5 would run up the power bill due to energy and a/c usage. I'd only be running the lights 9-10 hours a day as well. If advanced led's can give me a discount down to, say, 275 per DS100, that would get my total lighting cost down to *1650 if I did 3 layers of 2 1/2 ft deep by 6-7 ft wide. I could acquire that with a couple months of pay at my job.

That would be 10 plants deep by 28 plants wide, and at 3 layers of plants I would still be producing 840 plants per growth cycle. How much does one DS100 cost you guys in electricity per month? I'll try to run during twilight off-peak hours, which is 2.75 cents per KwH where I live iirc. EDIT: I did the math and with estimated A/C increase it would probably run me 75-150 a month depending on my efficiency.

Does anyone know how high above the pots a DS100 needs to be in order to reach it's total coverage area? That info would help me a ton. If it's 28" or less that would be perfect.

 

multipass

Active Member
What lighting/ventilation do you have in there and how hot does it get?
yo, I use this 400cfm fan -- http://www.amazon.com/gp/product/B002JQ14F8/ref=ox_sc_act_title_2?ie=UTF8&smid=A1DXN92KCKEQV4
But its on a speed controller at the very lowest setting.

I used to use 400w mh / 600w hps both dimmable. It would get pretty hot as I was just venting into the room. could get like 10+ degrees above room easy.

Now I use LEDs, hans pannels.. and they barly give off any heat. probably raise the tents by 1-2 degrees from room temperature.. pretty awesome.
I still use the fan, but not for heat... to move the humidity out of the tents.
 

matticusn

New Member
yo, I use this 400cfm fan -- http://www.amazon.com/gp/product/B002JQ14F8/ref=ox_sc_act_title_2?ie=UTF8&smid=A1DXN92KCKEQV4
But its on a speed controller at the very lowest setting.

I used to use 400w mh / 600w hps both dimmable. It would get pretty hot as I was just venting into the room. could get like 10+ degrees above room easy.

Now I use LEDs, hans pannels.. and they barly give off any heat. probably raise the tents by 1-2 degrees from room temperature.. pretty awesome.
I still use the fan, but not for heat... to move the humidity out of the tents.
So if I were to dedicate 50-75 square feet and used 6 x 100DS panels with the fan you use for ventilation without a tent, I should be able to replicate your 1-2 degree temp increase?
 

SnotBoogie

Well-Known Member
Matticus,

Dont take this the wrong way but there are just wayyy too many variables for us to just "predict" what will happen (as i said before).

you are jumping into something quite complicated, doing it on a large scale, and trying to get the quick and easy answer when really, if you are going to use LED (or anything for that matter) you need to understand it, in depth.

I would not want to shell out for 6 commercial panels (a couple month wages as you point out) without having a true understanding of what is happening- i.e to the point where you do not need to ask these questions.

Again i want to stress that this isnt meant to be a flame. Im just concerned that you are running before you can walk.
 

matticusn

New Member
Matticus,

Dont take this the wrong way but there are just wayyy too many variables for us to just "predict" what will happen (as i said before).

you are jumping into something quite complicated, doing it on a large scale, and trying to get the quick and easy answer when really, if you are going to use LED (or anything for that matter) you need to understand it, in depth.

I would not want to shell out for 6 commercial panels (a couple month wages as you point out) without having a true understanding of what is happening- i.e to the point where you do not need to ask these questions.

Again i want to stress that this isnt meant to be a flame. Im just concerned that you are running before you can walk.
Thanks for the input. I definitely have a lot of research to go, but I have a years time to get ready. It's hard to find a lot of info on using LEDs to grow arabidopsis. There's some university stuff, some of which I have read, but a lot of it goes off on discussing stuff very complicated not having to do with growing conditions.

Here's a quote from one of the scientists behind the project:

The plants we are initially using, need a lot of maintenance. They need quite particular growth conditions, eg not too much direct light, not too hot,
This makes me think it would be good to use lights with a lower intensity. These things aren't sun sponges like cannabis, so I have to look a lot more into this before I go off buying lights that may be too intense.
 

SnotBoogie

Well-Known Member
In that case i would certainly avoid any high-wattage weed growing panels. They will fry them :P

You should remember that the suggestions you will be given here as far as commercial panels are designed to provide light "to excess" for a plant that loves strong sun anyway.

I would suggest t5/t8/whatever, maybe not even high output (depending on that specifics of what they need) or, as i've said before, a DIY LED arrangement of some kind for less heat (though you dont seem keen :D).

Have you started researching what kinda soil conditions they like?

Im interested to see how this goes, sounds cool. cant wait to see photos during lights-out of your shed full of glowing plants. :P
 

matticusn

New Member
I did some math and research online and between 100-200 umol is the optimal lighting. To achieve about 175 I would, luckily, only need one fixture of two 5000 lumen t5 bulbs per 4'x2.5' shelf. That would bring me to a total of 6 fixtures covering at $600. I found the fixtures online including the bulbs at htgsupply for $100 http://htgsupply.com/Product-GrowBright-4-Foot-2-Lamp-High-Output-T5-With-Choice-of-Bulbs.asp

That brings my total lighting cost down to $10 per square foot. I would still be able to grow 960 plants in that area if it were maxed out.
 

djwimbo

Well-Known Member
I did some math and research online and between 100-200 umol is the optimal lighting. To achieve about 175 I would, luckily, only need one fixture of two 5000 lumen t5 bulbs per 4'x2.5' shelf. That would bring me to a total of 6 fixtures covering at $600. I found the fixtures online including the bulbs at htgsupply for $100 http://htgsupply.com/Product-GrowBright-4-Foot-2-Lamp-High-Output-T5-With-Choice-of-Bulbs.asp

That brings my total lighting cost down to $10 per square foot. I would still be able to grow 960 plants in that area if it were maxed out.
Now you're on track with what I was suggesting.

Cost:benefit

If you can cover the 4ft X 2.5ft area with 2x 54W bulbs, why not space them apart instead of one fixture? As you increase the distance from the light source, the intensity of the light diminishes significantly(fast with T5's). Instead of running 6 fixtures, look at it as 12 fixtures. If the space is 2.5ft deep, mount the two tubes 10-16" apart. VS one fixture in the middle with two bulbs. I don't know if it's worthwhile, but it's a thought to kick around. Depends on how you want to set it up.
 

matticusn

New Member
Now you're on track with what I was suggesting.

Cost:benefit

If you can cover the 4ft X 2.5ft area with 2x 54W bulbs, why not space them apart instead of one fixture? As you increase the distance from the light source, the intensity of the light diminishes significantly(fast with T5's). Instead of running 6 fixtures, look at it as 12 fixtures. If the space is 2.5ft deep, mount the two tubes 10-16" apart. VS one fixture in the middle with two bulbs. I don't know if it's worthwhile, but it's a thought to kick around. Depends on how you want to set it up.
If I can find a single bulb fixture for half the price of the double bulb it will be fine. Got any ideas?
 
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