# dimmable ballests



## jackinthebox (Aug 11, 2012)

has anyone tried dimming the power to emulate the fall of the year comeing on with lowering the wattage to the plants when they put they put them to flower.  
  something like running the 1K watt mh bulbs at 100% durring the veg time of 2 months at 18/6.   then cutting down the time to 15/9 at 100% for 3 days then going to 12/12 for a week or so.  then staying on the 12/12 running 100% for say 10hrs and dimming down to 75% for 2 hrs for several days.  then runnign at 1K for 9hrs and dimming down to 75% for 2hrs and then dimming down to 50% for the last hr.   
   I thought this might get the flowering stage really movein along since it would help the plant to feel the fall of the year is comeing along ?   just wondering if anyone has tried something like this or is it just blast em with the 1K the whole 12 hrs  best?   
   just thinking of something else to use these dimmable ballests for ?


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## The Hemp Goddess (Aug 11, 2012)

I really see no advantage to doing that.  I am not sure what you mean by "getting the flowering stage really moving along", but giving the plant less light won't be advantageous.  It is the lessening of the daylight hours that cause a plant to flower, not the lessening of the intensity of the light.  The only reason that I dim my ballast is if I am in a small space or if the heat gets too bad.


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## pcduck (Aug 11, 2012)

> is it just blast em with the 1K the whole 12 hrs best?



Yep


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## Leonardo De Garden (Aug 12, 2012)

It's pretty rare to find a scenerio where the dimmable function is useful.


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## juniorgrower (Aug 12, 2012)

I have never even used my dimming function.


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## The Hemp Goddess (Aug 12, 2012)

I moved my 600W to a 2 x 4 space and when the temps hit 100, I turn the ballast down to 400W.  Other than that, I have not used the dim function.  I also have not used the enhanced lumens feature either--how does that work anyway?


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## juniorgrower (Aug 12, 2012)

I was wondering the same thing THG.  Mine has a super lumens option also.  Its been such a pain dealing with the heat this summer that I didn't dare to up the juice any.


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## The Hemp Goddess (Aug 12, 2012)

juniorgrower said:
			
		

> I was wondering the same thing THG.  Mine has a super lumens option also.  Its been such a pain dealing with the heat this summer that I didn't dare to up the juice any.



That is one of those situations where the ability to lower the lumens is helpful.  It is awfully hard for me to keep temps in line with 600W in a 2 x 4 space when it gets over 100.


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## Wetdog (Aug 12, 2012)

The Hemp Goddess said:
			
		

> I moved my 600W to a 2 x 4 space and when the temps hit 100, I turn the ballast down to 400W.  Other than that, I have not used the dim function.  I also have not used the enhanced lumens feature either--how does that work anyway?



Pretty much by over amping the bulb and shortening its life.

600w in a 2 x 4 space? Surprised you could just keep it at 100.:holysheep: 

Go granny, go granny, go granny go! *Little old lady from Pasadena*

Wet


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## Old_SSSC_Guy (Aug 12, 2012)

Guess I'm alone on this one too, 'cause I use a dimmable Lumatek 1000s. All about flexibility.  Run them in the veg room at 600 watts when plants are babies and 750 watt as teens.  Just do it to save on electricity, but also use dimmable 1000s (never dimmed) in the flower room.  To me its cheaper to use uniform dimmable 1000s in both rooms than to spend money on multiple 600 watt or 400 watt systems.  Only use the overdrive 'Super Lumens' setting when I'm planning to change out the bulb in the next month so I can squeeze some extra lumens from an old lamp.

But I don't do it to emulate the sun or season.  I think its the spectrum of light rather than its intensity/volume that plants react to.


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## juniorgrower (Aug 12, 2012)

How much cooler does the light run at 600w compared to 1000w?


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## Old_SSSC_Guy (Aug 12, 2012)

To be honest - I don't know.  They are all run through 6" vent ducting so I've never measured the temp because I've not seen a shift big enough to get my attention.  Logic says they are running cooler.  

Stupid I know, but I still get a perverse kick out of turning the dimmable knob on an HID light.  Kinda fun to see 600 watts bump to 1000 in a simple twist without having to shut them down or anything.  I called Lumatek and made sure about that part.  They said you can twist the switch with the system running or not, no impact.  Add to the fact that they auto-sense 120 vs 240 volts and auto-sense halide vs sodium lamps is also a neato feature, whether they dim or not.


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## juniorgrower (Aug 13, 2012)

So you can switch them when they are running.   The shop owner that I bought mine from said I needed to turn it off before switching the watts.  Thanks oldssscguy.


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## 1lildog (Nov 25, 2012)

It's hot where I live and I use the dimmable feature almost everyday. I love it.


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## TheStickyIcky (Dec 16, 2012)

The thing that came to mind to me with my HPS was putting it down to 50% if I were going to put some clones under it to start them out. Never used it. But thought it might come in handy if I rooted some clones under CFL'S and I wanted to slowly switch them over to the HPS. But I'd imagine by that time, they'd be strong enough to handle it.


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## WeedHopper (Dec 16, 2012)

I would rather use better exhuast then less light.


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## jmansweed (Dec 16, 2012)

To truly "emulate" the seasonal light change, you first would have to emulate the intensity at any given season. With indoor lights, (including dimmable), our lumens never reach the Sun's output. 

IMO if you were to dim, to replicate the seasonal Sun, your simply applying less light when needed. At full application, our lights are weaker than a Spring or Autumn Sun.

Dimmable lights certainly have application. Many younger plants need less light intensity - I just don't see replicating seasons as one of them


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## 1lildog (Dec 17, 2012)

It's the middle of december and i still have to run ac. if i were not south unlike most of ya, i probably wouldn't want dimable either. i would rather use better exhuast than less light if that was my problem.


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## pcduck (Dec 17, 2012)

> To truly "emulate" the seasonal light change, you first would have to emulate the intensity at any given season. With indoor lights, (including dimmable), our lumens never reach the Sun's output.
> 
> IMO if you were to dim, to replicate the seasonal Sun, your simply applying less light when needed. At full application, our lights are weaker than a Spring or Autumn Sun.



The sun's intensity never changes, just the angle and what may get in the way(clouds). Clouds makes the lumen per sqft less and the angle makes more of the red light spectrum.

The sun has an approximately 10,000 lumen per sqft output.
Inside my tent I have 11,875 lumens per sqft.


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## 1lildog (Dec 22, 2012)

Old_SSSC_Guy said:
			
		

> I called Lumatek and made sure about that part.  They said you can twist the switch with the system running or not, no impact.



I really like this feature. :hubba:


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## jmansweed (Dec 22, 2012)

pc - Good point about the "actual surface" Sun's intensity, I suppose I meant how intense it is on the planet's surface given environmental conditions as you mentioned (angle/atmosphere etc). This subject always brings the conversation of lumens and spectrum up for me soo......

The amount of light the Sun pounds on us, does in fact, average out to far exceed our indoor grow rooms - primarily because no "sweet spot" exists outdoors and the power of the source. In sunny conditions,  massive swaths of the planet receive the 10,000 lumens your referring to - rather than the limited area below our bulbs that create our optimum growth space. Even with naked bulbs we loose intensity after only a few feet. That is the difference I should have clarified better. 

We have to consider a few things. First, the bulb manufacturers measure lumens by determining the total output of your bulb - all the way around it. If you were to take a bubble and encircle your light, all the light that passes through that bubble could represent lumens. With a light hood, we are directing those lumens produced on one side of the bulb onto our plants. The other side of our bulb must reflect it's light to reach our plants. This reflection seriously diminishes a large portion of our lumens. Indeed the manufacturer sites massive lumen output - this does not always equate to massive lumen applications in our grow-rooms. The math sure works well but placement and installation have immense effects on efficiency and realistic out-put.

How light falls to the Earth and how we apply light is what I think is important here. Different spectrums of light actually carry with them different lumen intensity. As the angle of the Earth and the atmosphere allow different light spectrums deeper penetration the amount of lumens that reaches us differs. This is a complicated science requiring an understanding of Watts, lumens, spectrum and lux.

Watts refers to how much energy is used to create light, lumens to how much actual light is produced and lux takes into the account the area in which the lumens are spread. (Lux also dictates how humans perceive lights intensity). Spectrum is what type of light is illuminating. As Pc said, under the sweet spot the average 1000 watt bulb produces between 10,000 to 12,000 lumens. However, the intensity of indoor lights diminishes quickly the farther away we get. Hypothetically, a square meter with an indoor bulb 3 feet above it does equal the same lux as outdoors. The lumens at the floor have diminished substantially. I realize our plants grow within this 3 feet I'm referring to but the science remains in terms of light.

Outdoors the Suns wattage is something near 386 billion, billion mega-watts (or something unfathomable like that ). This outrageous power generates heat and lumens with consistant lux. Given that Earth's atmosphere and environmental conditions are normal, the Sun far exceeds our indoor light's output. It's power generates similar lumens, yet far more lux with no "sweet spot". So yes, we can out-do the Sun's lumens but it needs context. Lumens are merely luminosity (how bright the light is). Per square meter, the Sun can produce between 30,000 and 100,000 lux psm while our indoor lights produce maybe 1000 lux psm. This is where I think things differ. Lumens per square meter is an important calculation for us in reference to calculating growth parameters and possible production but we cannot ignore watts per square meter (irradiance) when discussing comparisons of the Sun and indoor bulbs - it describes a major difference and represents the reasons some of us have produced mammoth plants outdoors and struggle to produce equivalent harvests indoors. The power of the Sun is simply to strong. Yes, typically our indoor environments create consistency and environmental predictability therefore frequently produce high quality marijuana but lumens are only one part of that scenario. 

With dimmable ballasts we are lowering not only lumens, but wattage and lux. As lux is already seriously diminished comparatively, dimming the light seems counter productive in my book. As we know different light spectrums carry with them different lumen intensity and if the goal here is to mimic the outdoors, then changing light spectrum seems more important to accomplish that goal. 

On the other hand, dimmable ballasts certainly have a place. Vegging to flowering for example (our veg requiring less lumens). Or simply an option to use less power. In terms of replicating seasonal changes in sunlight however, more complicated measures would have to be taken IMO. 

Heres a few links to read for yourselves: 

hXXp://solar-center.stanford.edu/about/ 
hXXp://www.energybooks.com/pdf/D1150.pdf
hXXp://en.wikipedia.org/wiki/Lux
hXXp://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=10630


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