HPS vs MH ! HPS overrated ???

TommyHobby

TommyHobby

Active Member
So I was bored today and decided to take a closer look at HPS and MH lamp color spectrum outputs.

What I've discovered shocked me a bit. From the diagrams I attached seems like the MH lights offer more BLUEs (no brainer) BUT in the oranges/reds they offer pretty much the same output at the sodium lamps.

Is this right? Wouldn't this make a MH setup more economical and more efficient than the HPS? someone explain.

View attachment 1067017 :hump: View attachment 1067018 :hump:
 
straitkilla911

straitkilla911

Active Member
Metal Halides produce more light in the blue side of the spectrum which is ideal for the veg phase.(root, stem, and leaf growth.) but HPS produce more yellow/orange (and some red light) which is necessary for bud growth on a flowering plant.

If you have the choice between two of equal wattage the HPS is the better choice as it produces more lumens per watt. Buds grown solely under MH lights will be airy and loose.

Here's a chart of relative lumen-to-watt output to help.

Incandescent("grow lights"): 17lumens/watt
Mercury Vapor: 45-50lumens/watt
florescent: 60-70lumens/watt
metal halide: 90 lumens/watt
High Pressure Sodium: 107 lumens/watt
 
TommyHobby

TommyHobby

Active Member
straitkilla911 said:
Metal Halides produce more light in the blue side of the spectrum which is ideal for the veg phase.(root, stem, and leaf growth.) but HPS produce more yellow/orange (and some red light) which is necessary for bud growth on a flowering plant.
Click to expand...
Did you look at the graphs I attached?
 
straitkilla911

straitkilla911

Active Member
Found this chart which was slightly easier for me to read:

MH


HPS


So although the two HID lamps share a similar spectrum range, The Metal Halide still fails to produce the amount of yellow/orange/red light the HPS does as well as a lower lumen-watt ratio
 
T

thalboy

Active Member
I strongly disagree that MH lights produce airy buds. That's absolutely not the case. A lot of growers are moving to MH only because they produce tighter, denser, nugs. The complaint most people have against MH is that the buds have too much leaf material. I haven't found that to be the case, although I've tried flowering under CMH instead of MH.

A grower shouldn't make all their decisions on lumens, as that is a measurement for humans, not plants. You could have a 1,000,000W bulb in the wrong spectrum and it would not work.

I suggest trying the CMH bulbs although they max out at 400. I'm did a CMH+HPS veg and now flower and I think its the best combo overall.
 
TommyHobby

TommyHobby

Active Member
straitkilla911 said:
So although the two HID lamps share a similar spectrum range, The Metal Halide still fails to produce the amount of yellow/orange/red light the HPS does as well as a lower lumen-watt ratio
Click to expand...
1. I agree with you on the lower lumen-watt ratio, making HPS setups a little more efficient in that aspect.
2. The charts I attached and the ones you attached seem to contradict each other. MH seems to produce more oranges than HPS in my charts. But then again, the Y axis scale wasn't specified...
 
straitkilla911

straitkilla911

Active Member
Yes it would appear as if they all seem to contradict each other. anyone have a truly accurate chart comparing HID lights of the same wattage .
 
Chillums

Chillums

Well-Known Member
As far as I can see (might be wrong) but if you could create a tungsten vapor buld of sorts it would be very close to daylight anyone else come to this conclusion?
Chillums
 
IAm5toned

IAm5toned

Well-Known Member
tungsten has one of the highest melting points known to man, far higher than the glass it would be encased in. just wouldnt work.
hps gives higher yields.
mh produces better quality.
 
TommyHobby

TommyHobby

Active Member
IAm5toned said:
tungsten has one of the highest melting points known to man, far higher than the glass it would be encased in. just wouldnt work.
hps gives higher yields.
mh produces better quality.
Click to expand...

just doesn't make sense... why?! is it the lumens? we all know lumens is just for us, not the plants... still confused.


btw, all those charts were taken from WikiPedia....
 
anomolies

anomolies

Well-Known Member
I still want to see a MH vs HPS test to settle the score.

Supposedly MH + HPS is the best but I have never seen anyone do it.
 
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