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The Basics Of Plant Lighting

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McCdive

Well-Known Member
:thumb: I'm really liking the camara idea! Never thought of that. I would be all over a light that could keep my eye on the room when ever I wanted! :thumb:
:high-five: Andy.
 

Whitty08

New Member
Hello everyone,
New grower here. Amazing thread. Couple questions, I'm currently running 4x6 T5 with two PowerVEG bulbs in a 4x4 gorilla grow tent. I'm only growing for personal consumption. Do I have adequate coverage? Next question, it was kind of answered earlier in the thread but is it completely necessary to switch out some of the 65k bulbs for the 32k bulbss for flowing? Thank you for the advice.
 

VonDankenhoek

On Vacation
hey whitty,

welcome. the guy who started this thread is rarely around. pretty sure he is real busy with work, life busy-ness etc. without him there isnt much lighting knowledge on 420 especially compared to other sites where experts congregate and debate lamp merits using facts and figures, experience and data sheets.
 

HydroDyna

New Member
A 150 watt MH/HPS lamp produces less heat than a 200 watt CFL right?
I know the surface gets a lot hotter but that has to do with the surface area I guess.
 

SuperFunker

Active Member
VonDankenhoek: Yes, unfortunately Hosebomber - thread originator - has not been around much. When he was more active, I typically 'tried' to do my own research, then I would regularly return to confirm with Hosebomber. He was/is a great source of inspiration and knowledge.

Whitty08 re 6500k vs 3200k bulbs: I think I can provide a tiny bit of guidance. Putting aside the specific technology (gas discharge, LED, etc), if you can switch to a warm light for flowering, do so. A typical 6500k light will emit most of its energy in the blue range (400 to 500nm) which is great for early vegetation (seedling/clones). In contrast, a warm bulb (3200k) will emit some blue light, but most of the energy will likely be yellow, orange and red (about 550 to 680nm). The orange/red light provides energy similar to the seasonal change in Fall which is when flowering occurs. Note: The preceding is a generalization.

PLIP, SuperFunker
 

SuperFunker

Active Member
HydroDyna the heat of 150 watt HPS vs 200 watt CFL: I am not sure which is hotter, but note a typical HPS is actually designed to work very hot. The heat is critical to chemical reaction that occurs in the bulb. I am not sure if a common CFL is "designed" to work hot to produce light or if the heat it produces is merely a byproduct. Regardless, if heat is an issue, I suggest investing in a decent LED. GL.

PLIP, SuperFunker.
 

VonDankenhoek

On Vacation
Guys there is a huge group of knowledgeable led builders who know the science and ignore the hype on another site that specializes in diy leds. Lots of tables and tests and comparisons. Quite a few diy guys making builds that compare with and out perform (at times) the best HID. The newest and most efficient tech is nothing like the led stuff you see adverstised here on 420.

Theres a led luminaire leap in quality taking place right now. Im building a pair of pontoons to add on to my optic vero 360. Adding 2x cree cxb 3070 to each end. Psyched to have learned enough to take a hands on approach to latezt tech.
 

SuperFunker

Active Member
VonDankenhoek... Yes, totally agree! The LED prototypes I have coming online are 10 to 50% more powerful than the newest LED grow lights. Details coming soon... :D

PLIP, SuperFunker.
 

Merriwanna

New Member
I'm a newbie to Indoor growing and don't know if it is for me. I am totally confused about LED lighting. How do you guys know all this stuff? I'm beginning to learn enough to be dangerous!

My problem : I purchased HydroMASTER 600W LED Grow Light 5W LED Full Spectrum Lamp for Plants Veg Flower

How much light / dark hours would you suggest for above lighting.

I put two white widow under when they were approx. 2 week old. The season has changed here in Perth Western Australia to Autumn warm days 18-23C and cool nights 12-9C - and I must confess the little girls were outside until my LED lights arrived. they would have been receiveing approx. 7 hrs light 17 dark. Snap .... I think I know why they are not looking so well at the moment.

They are not looking so well now. They looked burnt - but I've just realized my lights are on 24 hrs! that would burn any baby wouldn't it.

So.. on to my next lot of seeds..... what do you suggest for light / dark hours per day
 

HydroDyna

New Member
How reliable are these tests?



LEDs always seem to win, and I want to belief it but I have a feeling they may rig these tests so LEDs look better than they really are.
 

Graytail

Plant of the Year: 2014 - Plant of the Month: Dec 2014 - Nug of the Month: Feb 2015, Mar & Aug 2016, Dec 2017, Aug 2018, Jan 2019 - Nug of the Year: 2017 - Photo of the Month: June 2018
I have the XML 350 and it's a very good panel. :thumb:

One of the things that the comparisons overlook is beam spread/focus. A hps tube radiates in all directions with no focus except for the reflector. LEDs are focused. So, the plants right under an LED panel will do as well or better than under hps. But LED intensity falls off very rapidly once you move the plants to the side, and those will do better under hps.

In other words, in a 3x3 a 350 LED will do as well or better, but in a 4x4 the 600 hps will outperfom the LED. In a 4x4 you'd do better with four-100 watt LEDs because you're spreading the beam better.
 

VonDankenhoek

On Vacation
GT, the newest cobs are using lenses or reflectors. These can focus the beam for penetration and control the 120° light emitted by bare cobs.

For highest efficiency enough led cobs driven at sub nominal current eg .7 mA and well distributed across the panel will easily outperform the brightest HID (gavita DE) which at best are ~41% efficient vs up to 50%+ for cree cxbs.

Led lamps using blurple diodes are ridiculously inefficient vs high quality new tech cobs. The blurple luminaires are surpassed on every quality parameter by new cobs. Ask any manufacturer to compare the efficiency of their diodes vs vero and or cree. Claims made by led advertisers here on 420 are ludicrous.
 

Graytail

Plant of the Year: 2014 - Plant of the Month: Dec 2014 - Nug of the Month: Feb 2015, Mar & Aug 2016, Dec 2017, Aug 2018, Jan 2019 - Nug of the Year: 2017 - Photo of the Month: June 2018
My point is that everyone compares the source - the diodes/emitters vs the bulb. LEDs are a more efficient source. But in real life, plants are distributed over the entire space, while the LEDs (usually) aren't.

A 600 watt hps has an average of 700 PAR at 24 inches across a 4x4. One 350 watt LED panel will match that PAR within its focus, but that focus is a LOT smaller than 4x4. The LED manufacturers don't mention that. Four panels with 700 PAR and a 2x2 spread would be a fair comparison. One panel with higher PAR won't cover the full space, but will do great in the middle.

I'll be running a XML 350 in the center with a 175 watt Mars-Hydro in each corner. :3: That should take of the spread issue. :laugh2:
 
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