Another reason to move away from HPS

[thepaan]

As it turns out, photodamage has an action spectra. It looks a lot like an HPS plus a UV light to me....

http://www.plantphysiol.org/cgi/reprint/153/3/988.pdf

thepaan Reviewed by thepaan on 07-07-2010. Another reason to move away from HPS As it turns out, photodamage has an action spectra. It looks a lot like an HPS plus a UV light to me.... http://www.plantphysiol.org/cgi/reprint/153/3/988.pdf Rating: 5

[Rusty Trichome]

Gee...did you read the article...? Perhaps you should carefully look over the UV light threads here on CanCom. Pretty informative.

Doubtful I'll ever move away from my 1000w HPS. Produces a quality product. Also, I use supplimental UV light in flower. (for those that wish to try and use UV light, use proper care. UV can cause skin cancer and really does put you at risk for eye damage)

[neceros]

To be fair, I don't think any human can actually read that document without falling asleep.

[thepaan]

Oh! I guess, let me summarize it for you (see images). Doesn't that middle hump look strangely similar to an emission spectra of an HPS, or am I just imagining it?

[Rusty Trichome]

Gee. I thought it depended on the bulb. Some are full spectrum, some are for street lights or security lights, some are for growing indoors, some for aquariums... Most have so many friggin lumens, doubtful spectral bleeding is a problem worth a mention. Especially if results verify it's worthiness.

Perhaps you should get to the point. Explain why we should be as concerned as you seem to be...? I grow killer buds with my 1000w HPS, and have found no lighting system for indoor growing that even comes close to the performance of an HPS system. I'd love to see an example of this 'photodamage' you refered to. I'd also like you to look-up the degredation process of CBD to CBN, and it's effects on the psychoactive properties of the THC. Personally, I use the UV light to enhance this degredation further and quicker.

But I'm curious...what do you propose as a "better" choice?

[Dutch Pimp]

It would take a PhD or a dumbass to read that pdf...I read it up to the sixth grade.....:detective1:

[thepaan]

Gee. I thought it depended on the bulb. Some are full spectrum, some are for street lights or security lights, some are for growing indoors, some for aquariums... Most have so many friggin lumens, doubtful spectral bleeding is a problem worth a mention. Especially if results verify it's worthiness.

Perhaps you should get to the point. Explain why we should be as concerned as you seem to be...? I grow killer buds with my 1000w HPS, and have found no lighting system for indoor growing that even comes close to the performance of an HPS system. I'd love to see an example of this 'photodamage' you refered to. I'd also like you to look-up the degredation process of CBD to CBN, and it's effects on the psychoactive properties of the THC. Personally, I use the UV light to enhance this degredation further and quicker.

But I'm curious...what do you propose as a "better" choice?

I see you are easily inspired to bicker and difficulty inspired to discuss....

First, most street lights are actually LPS, not HPS. Second, I'm fairly certain all HPS spectral content is so similar that it is not worth distinguishing them. Any so-called HPS with a drastically different spectral content is actually high-pressure-something-else and/or metal halide.

I said nothing about being concerned. I am simply presenting new evidence for the this-light-vs.-that-light argument. in the hope of some intellectual conversation. Regarding that: I can agree that the quantity (or however you want to call it) of light is more important than the quality. Therefore I can agree that 1000W of HPS is far superior to 90W of LED. But still, it can't hurt to try to improve the quality of light. As you put it, referring to CBD, the quality of light can improve the end product.

In all plants photodamage occurs which primarily destroys a major part of photosystem II. This destruction inhibits photosynthesis, or slows it down. As everyone knows, it is via photosynthesis that the plant grows at all. So, paradoxically, light makes a plant grow slower but without light it will not grow at all. As we can see above, some wavelengths cause more damage than others. Most of this damage occurs in the UV wavelengths but there is also a peak just shy of 600 nm. This means that the damage to the photosystem is most severe at these wavelengths. There is a process to repair the damage but that process draws from the same energy pool which could be used for growth and then, as you asked, there is the point:

The highest quality light source shouldn't destroy any part of the plant which causes it to grow.

[Rusty Trichome]

I see you are easily inspired to bicker and difficulty inspired to discuss....

Unless it was your paper you submitted, all you did was cut-n-paste an article. No questions or comments from you, pro or con.
It's not that I want to bicker, it's that I would like you to tell us what the fuck is your concern or issue regarding HPS lighting.

First, most street lights are actually LPS, not HPS.

Oh really...? Big mistake not knowing what you're talking about. Other's might just know as much or more than you. Perhaps your local lights are different, but here...HPS.

"High-pressure sodium (HPS) lamps are smaller and contain additional elements such as mercury, and produce a dark pink glow when first struck, and a pinkish orange light when warmed. Some bulbs also briefly produce a pure to bluish white light in between. This is probably from the mercury glowing before the sodium is completely warmed. The sodium D-line is the main source of light from the HPS lamp, and it is extremely pressure broadened by the high sodium pressures in the lamp; due to this broadening and the emissions from mercury, colors of objects under these lamps can be distinguished. This leads them to be used in areas where good color rendering is important, or desired. Thus, its new model name SON is the variant for "sun" (a name used primarily in Europe and the UK). HPS Lamps are favoured by indoor gardeners for general growing because of the wide colour-temperature spectrum produced and the relatively efficient cost of running the lights.
High pressure sodium lamps are quite efficientâ??about 100 lm/Wâ??when measured for photopic lighting conditions. They have been widely used for outdoor lighting such as streetlights and security lighting. Understanding the change in human color vision sensitivity from photopic to mesopic and scotopic is essential for proper planning when designing lighting for roads."
High Pressure Sodium lamp - Wikipedia

Second, I'm fairly certain all HPS spectral content is so similar that it is not worth distinguishing them. Any so-called HPS with a drastically different spectral content is actually high-pressure-something-else and/or metal halide.

Hmm...lost me on that one. Going to have to show me the similarity in spectrums of HPS and a full spectrum HPS. Or perhaps a link to what the full spectrum HPS REALLY is. Not that I really care, as I will continue to use what I use. (cheapest HPS bulb available, on the day I need it) I'm personally not so anal as to require $150 bulbs that do nothing more than my $30.00 bulbs, so am comfortable with the possibility of "photodamage" regardless. Perhaps you could provide some pictures highlighting your concerns, as I have no problems at all with cannabis under HPS lighting. Never have.

But regarding the effects of UV light...if you are going to try and tell us the effects of UV light are undesirable, you are barking up the wrong tree. Some of us have found the benefits of using supplimental UV lighting (I use a reptile UV bulb, 7% at 8-12") and we use it with prior knowledge the damage it will cause the plant. Matter of fact, it's a result we intentionally strive for. There's a few threads regarding UV lighting here, if being a lighting guru is your thing, check 'em out. It'll help keep your foot out of your mouth when discussing lighting and it's effects.

The highest quality light source shouldn't destroy any part of the plant which causes it to grow.

Plants repair themselves daily from a myriad of injuries and issues.

LED's.............not there yet, expensive if of quality.
CFL's.............limited effective range, good for growth phase when plants are smaller
Fluoro tubes...even less range, good for seedlings and fresh clones
Grow spots.....more heat than lumens, cheap but garbage
MH................deep range, ineffecient, more bulb heat than HPS
HPS...............deep range, versitile, cheap, reliable, effective...

As I previously asked...what's your point? What's your alternative? What's the grand solution?

Seriously, the plant is fine under HPS, and any incidental or potential damage is negligable. The most you have to worry about is letting the plants grow too close to the bulb, or dropping the reflector on the plants.

[khyberkitsune]

"Oh really...? Big mistake not knowing what you're talking about."

Excuse me, sir. LPS outputs far more lumens versus HPS, which is why it's preferred in highway/parking lot/street/airport lighting. He most certainly DOES know what he's talking about.

Call my pal Jason Chambers of Memphis Concrete Cutting at (901) 365-9331. We used to install the things.

LPS = 180+ l/w, HPS = 140-150 l/w.

LPS is better for human visual purposes, or at least perceptibly brighter, which is EXACTLY WHY it's used in street lamps.

You only usually see HPS/MH in camera-recorded parking lots where color rendition is a requirement for video surveillance.

Really, Rusty, I also would have thought you'd know that LPS is used specifically because of the lower light pollution as well, which is why they're the *ONLY* choice of light used around astronomical observatories.

[thepaan]

Unless it was your paper you submitted, all you did was cut-n-paste an article. No questions or comments from you, pro or con.
It's not that I want to bicker, it's that I would like you to tell us what the fuck is your concern or issue regarding HPS lighting.

Well, I actually did leave a comment in the first post - maybe you missed it since it was so short. Also, I don't really have any concerns with HPS lighting as I don't use them but I hear they make a nice dent in your power bill... which can be a real nuisance if it gets exponentially more expensive every 100 kW h like mine does. Lastly, could you calm down a bit? Your posts read like a script starring Samuel L. Jackson. It is not my intention to personally attack you.

Oh really...? Big mistake not knowing what you're talking about. Other's might just know as much or more than you. Perhaps your local lights are different, but here...HPS.

I didn't say you don't know what you are talking about. I simply thought you made a mistake. I make mistakes too.

Hmm...lost me on that one. Going to have to show me the similarity in spectrums of HPS and a full spectrum HPS. Or perhaps a link to what the full spectrum HPS REALLY is.

All right, now we are getting somewhere! Like I said, I've never used HPS so I may be talking out my asshole here but as far as I know, a full spectrum bulb or dual-arc bulb is actually a combination of MH and HPS. Then there is your standard HPS which might have other stuff in there but the output spectrum pretty much looks the same. The full spectrum bulb still has the yellow from the sodium vapor but also gets a broad blue and green fill in from the metal halide so the overall output looks more flat - but theres still a huge spike in the yellow. Compare attachments. Am I wrong here? Lets take this with a grain of salt until we can check some more. Specifically, what is the exact bulb you are using?

Not that I really care, as I will continue to use what I use. (cheapest HPS bulb available, on the day I need it) I'm personally not so anal as to require $150 bulbs that do nothing more than my $30.00 bulbs, so am comfortable with the possibility of "photodamage" regardless. Perhaps you could provide some pictures highlighting your concerns, as I have no problems at all with cannabis under HPS lighting. Never have.

I concur. If you are happy with your setup then by all means, keep on keepin' on. And it is true that HPS are sufficient but then, not using UV is also sufficient.

But regarding the effects of UV light...if you are going to try and tell us the effects of UV light are undesirable, you are barking up the wrong tree.

Nope. I had no idea about the UV. I was only referring to HPS in the original post as I assumed that UV was never included because it has to be intentionally and seperately added to indoor lighting. I do thank you for that tid-bit of info and I might be expanding my practices later.