# Tried to Choose a Light and Cooked my Brain



## ChatNoir (Jun 20, 2008)

I literally did! I was thinking like "there are no retail sellers for light" yes it was true but it appears that Phillips have MH and HPS lamps. I found a catalouge but in the end got my brain cooked... My grow area will be 8ft² (2x4ft).

For price conversation 1$ = 1.2YTL~

The lamps I am looking for is at page 19 and 20. Catalouge might be in Turkish but symbols are the same.

Note: C&#305;va = Mercury. 

View attachment philips_aydinlatma_fiyat_listesi_08.zip


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## billy_fyshe (Jun 20, 2008)

you need 3 measurments
length x width x height
when you have this figure
you need to work out how many lumens you need
i think the minimum is 2000 per square ft

i got this guide from another web site


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## ChatNoir (Jun 20, 2008)

billy_fyshe said:
			
		

> you need 3 measurments
> length x width x height
> when you have this figure
> you need to work out how many lumens you need
> ...



Actually, my real problem with the list is "Ra" and "K" values. I will have two different grow spaces, one for veg & seedlings and one for flowering.

I know 5400K is good for vegetative but what about "Ra" and "K" value for flowering?

2500 is minimum lumen from what I read.


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## Puffin Afatty (Jun 20, 2008)

*lots of folks use HPS for both sides :hubba:*


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## billy_fyshe (Jun 20, 2008)

its 2700k for flowering
not sure what the 'Ra' is?
HPS is the best for flowering from what ive read
and from personal experience
i went from a 125w 2700k envirolight
to a 150w HPS and my yield is almost double


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## Runbyhemp (Jun 20, 2008)

> you need 3 measurments
> length x width x height
> when you have this figure
> you need to work out how many lumens you need
> i think the minimum is 2000 per square ft



You don't need to worry about height really. Multiplying length by width will give you surface area. Recommended light is 5,000 lumens per square foot.


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## ChatNoir (Jun 20, 2008)

Runbyhemp said:
			
		

> You don't need to worry about height really. Multiplying length by width will give you surface area. Recommended light is 5,000 lumens per square foot.



I will be using a 400W so probably around 5,000 lumen per 300cm²...

Any clue about "Ra" value? And I am not familiar with this kind of lamps, will they be able to shed light in full potential to 8ft²? Lamp is 28cm long (1ft~) and grow area is 120cm long (4ft)


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## Runbyhemp (Jun 20, 2008)

> My grow area will be 8ft² (2x4ft).



That means you'll have about 5,500 lumens per square foot


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## billy_fyshe (Jun 20, 2008)

Runbyhemp said:
			
		

> You don't need to worry about height really. Multiplying length by width will give you surface area. Recommended light is 5,000 lumens per square foot.


 
thats where ive been goin wrong then


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## Hick (Jun 20, 2008)

frpm here---> http://www.marijuanapassion.com/forum/showthread.php?t=1981



> color temperature n. unit of measure to express the color (spectrum) of light emitted by a lamp; the absolute temperature of a blackbody radiator having a chromaticity equal to that of the light source (see correlated color temperature).
> Lamps rated at 6500 degrees K radiate primarily in the blue/green portion of the color spectrum, which mimics the spring and early summer sun and is most commonly used for vegetative growth; those rated at 2500 K radiate primarily in the red/orange portion of the spectrum, which mimics the late summer and early fall sun and is commonly used to induce flowering.
> 
> kelvin (K) n. unit of measurement to express the color (spectrum) of light emitted by a lamp; the absolute temperature of a blackbody radiator having a chromaticity equal to that of the light source (see correlated color temperature).



  I'm not sure what the "Ra" represents, and I couldn't make heads from tails of the doc. you posted, sorry..


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## ChatNoir (Jun 20, 2008)

Hick said:
			
		

> frpm here---> http://www.marijuanapassion.com/forum/showthread.php?t=1981
> 
> 
> 
> I'm not sure what the "Ra" represents, and I couldn't make heads from tails of the doc. you posted, sorry..



There were two pages, but with new info I have checked those pages and I have a few questions.

MH

HPI Plus 400W/767DL BU E40 (with SON Balast) has 42,500 lumens but only 5400K 106lm/w

HPI Plus 400W/767DL BU E40 (with HPL Balast) has only 35,000 lumens but has 6400K spectrum. 87,5lm/w

HPS

SON-T400 W Agro has 55,000 lumens but 2000K 137,5lm/w

These are the best from the list or should I stick with tube flourescents instead of MH lamps which has 135lm/w effectiveness and use HPS for flowering?


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