MH vs HPS for yield?

[rives]

I think that HPS works well simply from being very efficient at turning electricity into light, combined with the fact that plants are pretty flexible as a result of being survival-driven.

As to what optimizes all of the other aspects of the plant beyond straight growth rates, I think that it is pretty foolish to think that a plant that has evolved under full-spectrum light for millions of years is going to excel under narrow bandwidths of light. They can certainly get by with it, and perhaps even bring out certain characteristics more than others, but to equal all of the characteristics of a plant grown in it's native habitat? It flies in the face of reason.

 

[Drek]

This is the problem with systems analysis, without considering the impact of evolution. As time goes by, we learn more...

 

[RB56]

I think that HPS works well simply from being very efficient at turning electricity into light, combined with the fact that plants are pretty flexible as a result of being survival-driven.

As to what optimizes all of the other aspects of the plant beyond straight growth rates, I think that it is pretty foolish to think that a plant that has evolved under full-spectrum light for millions of years is going to excel under narrow bandwidths of light. They can certainly get by with it, and perhaps even bring out certain characteristics more than others, but to equal all of the characteristics of a plant grown in it's native habitat? It flies in the face of reason.

Well this is the gist of it. I think we risk making poor decisions, even define poor objectives, when we make such assumptions. Why not bombard plants with all of the EM spectrum they'd see in nature? I can't see anyway to get to plants needing just the spectrum that is visible to us without anthropomorphizing the plants.

OR by assuming an intelligent designer who didn't want to waste anything.

I think this:

I think that it is pretty foolish to think that a plant that has evolved under full-spectrum light for millions of years is going to excel under narrow bandwidths of light.

is equivalent to saying you need to buy everything in the hardware store because you need a tool. If you need a screwdriver, you need a screwdriver.

Pretty sure that plants optimized for photosynthesis using the entire visible spectrum would be black.

There's one other prejudice I can see in this. What if daylight provides 100 times more energy than is needed for optimal function? There's got to be a point where more light isn't helping. Color selectivity could be a protective mechanism in sunlight that completely works against us under artificial light. Alternatively, an abundance of available energy would have stopped evolution because there's no survival benefit from processing more "fuel" than you can use. There is nothing about the process of evolution that implies a perfected end point. There's good enough for what we're doing and better enough than the next guy to out-reproduce him.

The Philips CDM Elite Agro 315W appears to have the most even distribution I've seen. If white light is the goal, it could be king. I'll definitely look into it for a future upgrade. Might want to play with LEDs and see what is possible with precise color control instead.

 

[rives]

Well this is the gist of it. I think we risk making poor decisions, even define poor objectives, when we make such assumptions. Why not bombard plants with all of the EM spectrum they'd see in nature? I can't see anyway to get to plants needing just the spectrum that is visible to us without anthropomorphizing the plants.

OR by assuming an intelligent designer who didn't want to waste anything.

I think this:


is equivalent to saying you need to buy everything in the hardware store because you need a tool. If you need a screwdriver, you need a screwdriver.

Pretty sure that plants optimized for photosynthesis using the entire visible spectrum would be black.

There's one other prejudice I can see in this. What if daylight provides 100 times more energy than is needed for optimal function? There's got to be a point where more light isn't helping. Color selectivity could be a protective mechanism in sunlight that completely works against us under artificial light. Alternatively, an abundance of available energy would have stopped evolution because there's no survival benefit from processing more "fuel" than you can use. There is nothing about the process of evolution that implies a perfected end point. There's good enough for what we're doing and better enough than the next guy to out-reproduce him.

The Philips CDM Elite Agro 315W appears to have the most even distribution I've seen. If white light is the goal, it could be king. I'll definitely look into it for a future upgrade. Might want to play with LEDs and see what is possible with precise color control instead.

I think that you are putting way to much stock in "science's" ability to determine an organism's needs. For example, we are bombarded with new discoveries about human nutritional needs on an almost daily basis, and we should certainly have a better handle on that than on the lighting requirements of a plant. Our understanding of the physical world is very limited and highly biased toward the things that we can measure and understand to some extent. This level of "understanding" changes pretty damn quickly, and frequently bears little resemblance to the earlier postulation. For example, look at the information that has come out on green light recently and contrast that to the former "settled science" (like there is such a thing).

In 30+ years of growing this plant, I've used just about everything available with the exception of plasma. Having used precisely the same setup, with the same cultivars, the same nutrients, and the same environment and having jumped immediately from .6-.7 gpw (fully optimized) to .9+ gpw (still experimenting) with no other change than going from LEDs to the 315 CDM with 25% less power used, I am relatively certain that there is something about the light that the plants thrive under.

And in fact, that something is largely irrelevant to me. What matters most is that I prefer looking at the plants under white light. But it vividly demonstrates, in my mind at least, that our understanding of the plant's needs is woefully incomplete.

 

[hells winter]

Hello.
Can someone link/recommend a MH with 3000kelvin? 'Cause the growshop i get my stuff from hade no luck with his disributors. So he asked my if i know a brand that could have a 600w MH 3000 kelvin.

thx in advance .

P.s. while some don't like these kind of discussions i would like to say thx to all the info these kind of threads have to offer D.s.

HW

 

[Drek]

Hey HW.

There's a decent amount of 3-4k halides out there. The choice lamps for me are any of the Philips products, specifically (for med wattage) the 315 Agro. For higher wattage the CDM860 is there @ 4k. 4k has proven to work very well on most strains as a single bulb solution, with the additional benefits that halide offers. Sunmaster, Solistek and the Sylvania's that Gnome's using are all good choices. Arc protection (open fixture rating) is something that's important for me whether the fixture is open or closed, as I like a protected arc. Depending on the engineering requirements (arc temps/pressures), protection may or may not be an issue tho...

 

[fabvariousk]

@hells winter
https://www.1000bulbs.com/product/88222/PX-MPS6003K.html
This site is all you need for bulbs.

 

[Jhhnn]

Hello.
Can someone link/recommend a MH with 3000kelvin? 'Cause the growshop i get my stuff from hade no luck with his disributors. So he asked my if i know a brand that could have a 600w MH 3000 kelvin.

thx in advance .

P.s. while some don't like these kind of discussions i would like to say thx to all the info these kind of threads have to offer D.s.

HW

At 600w, I think you'll need a dual arc lamp for that. Just an example-

http://www.gothamhydroponics.com/featured-products/600w-dual-arc-bulb.html

I have no experience with that particular lamp. I get excellent results with a plantmax 1000w dual arc.

 

[the gnome]

Hey HW.

There's a decent amount of 3-4k halides out there. The choice lamps for me are any of the Philips products, specifically (for med wattage) the 315 Agro. For higher wattage the CDM860 is there @ 4k. 4k has proven to work very well on most strains as a single bulb solution, with the additional benefits that halide offers. Sunmaster, Solistek and the Sylvania's that Gnome's using are all good choices. Arc protection (open fixture rating) is something that's important for me whether the fixture is open or closed, as I like a protected arc. Depending on the engineering requirements (arc temps/pressures), protection may or may not be an issue tho...

yup fab, 1000bulbs has excellent selection,
i found a Gnome approved 1Kw 4000K MH with a shatterproof bulb rated for open fixture for $40ish.
I'll be phasing out my 4000k sylvie's and replacing with that one if it does as good as what i have now.
its twice the cost but still @ $40 its all gravy imo

 

[the gnome]

I just found this@growers house
a 900w CMH bulb that runs with a digi/hi freq. ballast.
I bet it'll run on any 1000w digi ballast, i can't find the bulb to be by it's self anywhere
it comes as a paired bulb to ballast package, a bit pricey tho
i give it a while and were see variety go up and prices come down with CMH
K rating on it is a Gnome approved 4000K compared to the CDM 860 w/3700K

wish i could just get the bulb alone

http://growershouse.com/tru-sun-900w-ceramic-mh-system-by-dna-lighting

looking at the charts for HPS MH and CMH the CMH's are pretty damn tough!
with the advances in CMH bulbs i see coming, HPS manufactuers have a serious threat in a way
blockbutser video rental stores experienced when netflix started to get its share of the dvd rental market
http://www.maconmarques.com/wp-content/uploads/2014/04/900WCutSheet.pdf

 

[Drek]

Gnome, I'm pretty sure that is the Philips CDM860...re-branded with a more efficient ballast. CDM860 is rated 4K(3700k technical).

 

[the gnome]

Drek,
I was so interested i called tech @DNA and chatted it up for quite a while
and your spot on, it's a Phillps CDM860
i asked about just getting the bulb and running it on a standard digi ballast unless there was a special what not in their digi ballast to run the bulbas they offer it paired to an e-ball.,
but he said they no longer offer the e-ballast,... there's just too many probs running it on a hi freq. ballast with current technology


soooo I'm back to square 1

 

[rives]

Gnome, are you trying to avoid magnetic ballasts, do you want to stick with your existing ballasts, or what disqualifies this for you?

 

[the gnome]

it's the heat issues with mags,
i have 6-1KW mags in the new room because of $$outlay in the room build.
took temp readings with the laser and they are pushing @155-164F
lots of heat in the room w/6 and they have to be in there.
so i bought 3 nanoluxes and they run @94F
I planned on replacing the other 3 mags but i may just get 3 of the CDM860s and see how they perform.
looking at the spectrum charts I'm confident they blow away hps
and my 4000k halides can do what HPS does sooooooooo

lol...kinda fell on me like a load of bricks in short order today,
reading your post/484 at the top of the page, less power consumption, GPW increase worthy of noting.
comparing charts against my halide and adding all tis in the mix.
imho they are the future now for indoor gro's using 1 bulb in veg-n-bloom

 

[Drek]

Here's a couple charts(borrowed from another site). If we have a look, we'll see that the lamp on the left appears to have a higher energy output at less used wattage. This is because(I think) the internal arc temperatures are allowed to run hotter giving off more light(with the higher temperatures comes higher pressures too, hence the need for wire protection); ..the ceramic material being better at reflecting and containing the heat than quartz(on a QMH), makes it a bit cooler too. The lamp on the right is good too. Take away the yellow and it actually has more blue than red, and is a little lower in relative energy output, while giving off more heat.

 

[the gnome]

I agree Drek, the photometric data you posted looks excellent compared to either MH/hps

the spectrometer data is impressive as well, compared to natural sunlite

but when you compare the cdm860 against a 2100K hps or 4000K Mh
it's pretty clear how things stack up between the 3
check the link and scroll over the graphs and compare
it looks promising for sure

http://dnalightingsolutions.com/products.html
^^click on the compare link option in this link^^

 

[rives]

it's the heat issues with mags,
i have 6-1KW mags in the new room because of $$outlay in the room build.
took temp readings with the laser and they are pushing @155-164F
lots of heat in the room w/6 and they have to be in there.

Have you considered changing the ballast enclosures around so that you can vent the heat easily?

For instance, I use a 6' long piece of 8" x 8" electrical gutter to mount my ballasts and power relays in. You could easily use a chunk of gutter big enough to fit your ballasts into and run ductwork from outside the room to blow through the gutter. You might pick up a bit of radiant heat from the gutter, but with adequate airflow it would be damn little and the ballasts would last longer to boot.

 

[Jhhnn]

Have you considered changing the ballast enclosures around so that you can vent the heat easily?

For instance, I use a 6' long piece of 8" x 8" electrical gutter to mount my ballasts and power relays in. You could easily use a chunk of gutter big enough to fit your ballasts into and run ductwork from outside the room to blow through the gutter. You might pick up a bit of radiant heat from the gutter, but with adequate airflow it would be damn little and the ballasts would last longer to boot.

Excellent point. As an alternative, it might be possible to duct room air past the ballasts & then to the A/C intake, transferring that heat outside the room as it's created.

 

[the gnome]

nice idea rives,
Ive thought about doing something along those lines but It would have to be air tite.
I'm sealed w/Co2. and venting is an issue which 1 reason I'm sealed.
Q for ya... how long can i run a cord from the ballasts to the lights?
and again from the outlets to the ballasts, ive read some digi's have 50ft cords to lamps... maybe??
I'm on 220v if that has anything to do with anything

 

[Drek]

I agree Drek, the photometric data you posted looks excellent compared to either MH/hps

It follows the response curve pretty closely. CDM lamps are basically a mix of the two tech's; HPS (ceramic tube) and Metal Halide(halide salts and mercury). The wave of the future.

http://en.wikipedia.org/wiki/Ceramic_discharge_metal-halide_lamp

but when you compare the cdm860 against a 2100K hps or 4000K Mh it's pretty clear how things stack up between the 3 check the link and scroll over the graphs and compare it looks promising for sure

http://dnalightingsolutions.com/products.html

Design initial lumens are 82,000; 1838 uMoles @ 860w should provide nice growth while being able to better to observe the plants condition(compared with say, 2100k HPS). 20,000hr average lifetime too. In theory, it's pretty damn nice lamp for Horti single-use.