iso info 600w hps ballast compatible lamps for veg growth

cardiocriniumDecember 14, 2007

Hey folks. New member here. Nice place!

I just bought three used 600w HPS grow-light systems (at a awesome price). Now trying to decide on new bulbs to buy. Want to winter-grow a broad scope of seedlings and young plants in my no-sun basement so vegetative growth is my focus. I want to stick with HID equipment and preferably my 600w HPS ballasts as are. I'd consider kit-converting part of my ballasts to MH/CMH but please, no off-thread discussions of fluoro's.) :)

Have read all the vendor and marketing hype so looking for hard data and/or personal experience with bulbs. Have short-listed several HPS compatible bulbs. Particularly looking for info on Life Light Technology's 600W Sun Pulse Metal Halide Retro series. Series includes a 3K, 4K, 6.4K and 10K. The higher K ones draw attention but I can't find any decent spectral/PAR/PUR etc info. The one vendor I've seen for the bulb didn't know much. I emailed Life Light Technology asking for info. Haven't gotten a reply. Typical, don't ask questions, just buy our "better than anyone else's" product!

Eagerly awaiting the anticipated 600w CMH HPS compatibles, especially a 600w Philips Mastercolor HPS-retro, but until then, I've got some seeds to grow! Thanks

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My favorite lamp is the Gavita or other reflectorized look-alike. Really superior lighting pattern. I've had great results with that lamp. just keep it well well well away from the seedlings or they'll just get bleached out and die.
Paul Mozarowski.

    Bookmark   December 15, 2007 at 10:23AM
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shrubs_n_bulbs(z8/9 UK)

Some more information that you may find helpful:

1. Lermer is here primarily to sell ceramic metal halide bulbs, specifically Life Light brand lamps. The technical information in the table is very helpful but regard any performance claims for the lamps with a touch of salt.

2. Conversion lamps are generally shunned for poor performance. Specifically, short lives, terrible lumen maintenance, and even lower up front performance. The preferred solution is to get a switchable ballast, these are almost the norm now for a quality electronic ballast and provide optimal performance with either lamp type. Pulse start lamps do at least run on an HPS ballast with good performance but they are very hard to find at 600W. While any pulse start lamp is likely to run on any HPS ballast at the right power level, exact specs may vary and you could get poor performance if you use one that isn't specifically marked as "Retro" for HPS ballasts. I'm a little concerned about the 135V rating on these bulbs, that is not what I would expect to see on a "retro HPS" bulb but rather is a perfectly standard pulse start metal halide arc voltage.

3. You may find that lamps like the Hortilux Super HPS work as well as the metal halide but hard to be sure without comparing them directly.

Now excuse me a moment while I return to Lermer-bashing:

Lumens are for the human eye, NOT a measurement for plan
Marketing gobbledygook used by everyone that wants to claim their light is better than everyone else's. Lumens are a perfectly good way to compare white light sources for the purposes of plants, not perfect but as good as any other and in practice the only one available for nearly all white light sources. Because lumens are weighted to count certain wavelengths more than others, lumens may be a wildly inaccurate measure for light sources which are not more or less white.

For plants use Foot-Candles: FT-CD = Lumens divided by 12.53
I thought you said we can't use lumens for plants? But foot-candles are just lumens per square foot! The calculation for converting the lumens of a point source radiating in all directions to the foot-candles on the inside of a one foot sphere would be 12.566 (not quite 12.53 but nice try). Of course we are not dealing with point sources radiating in all directions and we are mostly not planting on the inside of a one-foot sphere. Luckily we are planting on flat surfaces which can easily be measured and we use reflector systems which put the majority of the light onto that flat surface. Divide the lumens by the square feet of the surface to get foot-candles. 10,000 foot-candles is approximately direct sun at noon in the tropics, 1,000 foot-candles is bright shade, 100 foot-candles is indoors during the day, 1-10 foot-candles is indoor artificial lighting for humans. Wow, plants need a lot of light! But remember you don't have to simulate the intensity of direct sunlight since you can maintain full light intensity for 12-16 hours, maybe even 24 hours. 2,000 foot-candles is generally sufficient for full sun plants, 4,000 is used by some but not for long hours, and cannabis growers often use even more than that on their hybrid plants.

Plants require full spectrum, high frequency light thats measured in footcandles or watts per meter sq.
Plants don't care much about full spectrum, use it if you have it but don't mortgage your life for it. High frequency light? What's that? You have no clue do you? You just read it in a marketing leaflet somewhere, its meaningless rubbish. Foot-candles, yes very handy for estimating how much light you need. Watts per meter sq, you are going to have to clarify. Is that input watts to the light? Output watts? Those mysterious PAR watts that lamps sellers like to confuse you with? Given that all the (high quality) white light sources that we use as plant light sources produce approximately the same lumens from each watt, watts per square foot can be considered a good guide in the same way that lumens per square foot can. Those same light sources all convert approximately 30% of their input power into light, but light output watts can be better than lumens for comparing with radically different light sources such as far red LEDs. PAR watts theoretically measure the light output of a lamp in the visible spectrum. In practice this is not a standardised measure, it is only used by lamp sellers to promote their products and you should treat it with some scepticism.

    Bookmark   December 15, 2007 at 4:59PM
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Shrub n Bulbs,

Give him time, you will be buying from him spinning high frequency lights with Life Light brand bulbs!

dcarch :-)

    Bookmark   December 15, 2007 at 9:05PM
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shrubs_n_bulbs(z8/9 UK)

I'm designing a system with four 250W Envirolites on the ends of a ceiling fan. Get an intense compact light source, then spin it to "spread" the light, you know it makes sense!

    Bookmark   December 16, 2007 at 12:34PM
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shrubs_n_bulbs(z8/9 UK)

I forget to mention that I am going to put my whole greenhouse on a turntable because it is impractical to rotate the sun so I will rotate the plants instead ;)

    Bookmark   December 16, 2007 at 12:46PM
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I am surprised at you, come on, you are normally so clever.

Your spinning ceiling fan/light is super, almost perfect. It needs one more thing.
How about adding an automatic watering system? Fan/light/watering, wow!

dcarch :-)

    Bookmark   December 16, 2007 at 12:49PM
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Thanks guys.

Object16, I'd been reading up on the Gavita internal reflector bulbs, referred to as a Reflux lamp line. Hadn't gone directly to their site. Just did and it has stuff I hadn't seen. Will explore.
(Readers, pardon that I haven't figured out to insert a hyperlink in this forum yet and can only paste in a text URL. Hyperlink posting seems to work differently than I'm used to. I'll try to find the right way. Any tips?)
Reflux appears to originate from a Chinese company, ReLighting Corp. Their website used to work find for me but now refuses to be English friendly and basically unuseable by me. Here it is anyway,
I found this link, , and from the light spread diagram there I was able to estimated the light at 1 ft down from bulb would be 5.5 ft across in the orientation of the diagram and at 2 ft down
would be 11 ft across. Perhaps I have mis-estimated. If I'm in the ballpark, seems you'd have to overap light zones to get much light intensity out of them. Since you use one, you can enlighted me with your experience.

Readers, in another thread, Object16 provided a link to an article comparing aquatic plants light bulbs.
Bravo object16. It is amazingly informative. The author explains how to compare bulbs, explains terms and I believe he gets it right. Fairly technical but worth several rereads. If anyone can lead me to other articles like that, please do.

Shrubs and bulbs, I'll look closer at the performance issues you raised about conversion bulbs. Yes, I am dissappointedly aware that there currently are no PSMHs in 600w. I would try one out in a heartbeat if there was one of suitable spectral performance and it was compatible with my current ballast. PSMH is still on my short list of candidates for kit-conversion but as I noted before, the 400w and 1000w seem easy to convert to but set-up implications of those wattages don't thrill me. PSMHs come in 750w, which would be much more attractive but it, as well as the 450w and the 875w, seem to present some tech hassles or obstacles. I'm continuing to explore for an attractive way to convert to a 750w.

Three 1 yr old Hortilux Super HPS bulbs came with my systems and I think they have some more useable life, at least for my purposes. I intend to keep at least one system using those bulbs over mature houseplants. Since I'm only using the bulb in winter, I hope to get 3 seasons' bulb use. Have one in use right now and I don't get the sense that it alone provides the seedling/vegetative light I'm seeking. Some ailing seedlings I have, have reacted very positively once I placed them under my recently acquired generic bulb (250w) MH system (lot of blue light). I'm planning to use two higher wattage lights over my seedling nursery. Since I'll be growing a diversity of species, I'm increasingly positive that I will select one bulb that provides a fairly broad PAR spectrum and match it with a bulb with a definite blue end bias, but ideally is fairly broad across the PAR blue end. I might use one of the Hortilux bulbs as one of the two, but I'm leaning away from that.

Ideally this thread will focus on a narrow product line. If people want to read or jump into discussions/debate about plant lighting terminology and technology in general, there are two preexisting threads still active in this sub-forum that are interesting reads. Perhaps there are others folks can link us to.

Again I apologize for not using hyperlinks.

    Bookmark   December 16, 2007 at 4:36PM
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shrubs_n_bulbs(z8/9 UK)

You can insert a hyperlink by typing in the HTML directly.

Is there something about the Life Light that you are concerned about? Other than some of the specs looking just the teeniest bit exaggerated, they seem to fit the bill for what you want. At the worst, they have a standard metal halide spectrum and you'll be fine. At the very very worst, they are a load of rubbish and fail after a year, then you can swap in a Philips Mastercolor which should be available by then ;)

    Bookmark   December 16, 2007 at 5:51PM
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Shrubs n bulbs: "You can insert a hyperlink by typing in the HTML directly."
You mean base HTML code? Never learned to compile HTML. Went to a tutorial site. Man, so tedious. I hope readers don't begrudge having to cut & paste URLs. A text URL is better than none at all. LOL

Shrubs n bulbs: "Is there something about the Life Light that you are concerned about?"
lermer offered a PDF spec sheet via email but I was hoping that there was a public access source. He did kindly provide a spec set in the thread but couldn't format as a table. Since I can't insert even a lowly hyperlink, I cannot begrudge lemer. I tried to decipher but couldn't get things lined up enough for me "figure it out". If anybody wants to lead me by the nose, the 6.k and the 10k are the only bulbs I'm interested in. One would hope that Life Light indicated confidence in their products by providing publicly accessible basic specs. Now if offered a gift Sun Pulse 600w PSMH retro horse, then I wouldn't want to look inside his mouth as badly.

Have a few weeks before I start seeds so need to rush to buy. A tad remorse for having bought three, instead of 1 or 2, 600w HPS ballasts before I had fully realized their limitations for my needs (as in maybe I should have shopped longer?). One ballast is already earning its keep. The other two may require more customizing than I had expected. But at the price I got the whole equipment lot, I'm still happy with my purchase.

Did you check out the article I referenced in my last post?
I really liked the way the author (Busko) takes the 'inadequate' bulb specs provided by most manufacturers and uses them to derive specs much more useful for comparing plant bulbs. Debating his methodology and a buyer's wisdom in using it would make a wonderful thread of its own. (BTW - I ran across two threads in aquarium forums where the article is referenced and apparently some folks more savy than I think highly of the article. Again, thank you object16 for the link. The market and buyers community for aquarium aquatic-plant lights appears to be more sophisticated than for "land" plant lights.)

I often enjoy researching my buys but the plant-lights market is revealing itself to be a real zoo!! It's obvious there's not much desire on the part of bulb-makers/vendors to market potentially useful plant-bulbs in plant-centric terms.

Bottom line, I guess I would be a lot more content if I could simply get a decent readable spectral curve (of ANY type) for each of my prospect bulbs. Using the logic of the Busko article, with what other info it seems to be pretty easy to scrape up, I think I could come pretty close to picking the best bulb for my needs all things considered.

Should I be taking it that there are very few people following these plant-light threads?

    Bookmark   December 18, 2007 at 12:32AM
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meant to have inserted this before. interesting numbers relative to sunlight PAR

    Bookmark   December 18, 2007 at 12:43AM
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shrubs_n_bulbs(z8/9 UK)

Don't get hung up too much on that article. It is thinking about the right things, and much of the information in it is useful, but the author has a very limited understanding of the subject and is speculating wildly, sometimes getting the wrong answer.

I am still trying to find a table I used to have, of what this author calls his "X factor", for other light sources including metal halides and HPS. Not the end of the world, but frustrating. One amazing thing that you find when you look at a wide range of (fluorescent and HID) light sources converted to photon fluxes (PAR) is that they are all very similar. The high lumen sources also have high X factors (lots of green and yellow light), so the photon flux always comes out in a relatively narrow range (at a given power). HPS tends to come out on top for sheer number of photons, old technology fluorescent or metal halide perform poorly, but modern (pulse start or probe start before they get dim with age) metal halides and fluorescents (triphosphor or new tech halophosphate) are all sitting within about 20% of the same efficiency measured in photons/watt. So I just don't get hung up on it any more. I choose a suitable power for my plant growing area, get a reasonably efficient light at a sensible price, with long life and good lumen maintenance, then make sure that all the light gets onto the plants. Most people obsess about a particular type of spectrum, light technology, or weird gadgets like spinners, but fail miserably to put the light on the plants and end up wasting half of it.

The author also refers to "spikiness" in spectra and lack of it in the plant growth spectral response. His implication is that wide non-spiky light sources are best, but the logic is flawed. Simply because a plant can use light of any wavelength more or less equally well does not mean that it must have every wavelength to grow well. Plants use virtually any kind of light you throw at them, whether it is a bit at every wavelength or nearly everything at a single wavelength. One thing you might want to consider is that plants adapt to both the intensity and spectrum of the light they receive by producing more or less of certain photosynthetic pigments, altering the structure of the chloroplasts, and changing the shape and orientation of their leaves.

    Bookmark   December 18, 2007 at 7:57AM
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(Shrubs) "Lumens are a perfectly good way to compare white light sources for the purposes of plants, not perfect but as good as any other and in practice the only one available for nearly all white light sources. Because lumens are weighted to count certain wavelengths more than others, lumens may be a wildly inaccurate measure for light sources which are not more or less white."

(Lermer) You're starting to understand. Lumens is not the only factor, CRI is not the only factor. Ideally you want PAR but manufacturers generally do not provide that information. So, again, I recommend paying attention to both lumens and CRI to get a rough estimate of PAR.

(Shrubs) "Conversion lamps are generally shunned for poor performance"

(Lermer) Generally that's true. But not all retros are equal. The Philips CMH works fine on the 400w magnetic HPS ballast. To my knowledge, there are no magnetic ballasts designed for CMH bulbs. This is probably because CMH hasn't been around for as long as HPS has, and now electronic ballasts are starting to become more popular compared to magnetic. The CMH has a ceramic arc tube, like HPS, which might explain it's greater efficiency on magnetic HPS ballasts compared to other retros. CMH has been field-tested for about 9 years, and for most people the results have exceeded HPS by about 50%. CMH on e-ballasts are about 15% better than CMH retros on magnetic ballasts.

To get a ballast designed to operate the CMH, I think you need to go with an electronic ballast. Life Light has designed an e-ballast that powers both their CMH bulb (not the Philips retro) and PSMHs. It is the only e-ballast that can power a 400w CMH bulb, and the Life Light CMH bulb is the only CMH that will work on an e-ballast.

Life Light has PSMH up to 600 watts, one kind works only on 600w HPS magnetic ballast, the other kind works only on 600w e-ballast. The spec sheet is not available online at this time. The spectral charts have been promised.

(Shrubs) "High frequency light? What's that? You have no clue do you?"

(Lermer) Do you deny that the sun produces light in pulses?
What is the support for your steady-stream theory of sunlight? I do not get most of my information from sales literature. Where do you get yours? Surely, they teach evolution in Britain--why then do you appear to deny that plants have evolved to full-spectrum light?

(Shrubs) "Given that all the (high quality) white light sources that we use as plant light sources produce approximately the same lumens from each watt, watts per square foot can be considered a good guide in the same way that lumens per square foot can."

(Lermer) That's true tautologically, since you specified "high quality". But not all light sources produce white light, and not all white light sources are efficient in terms of PAR per watt.

(Shrubs) "I forget to mention that I am going to put my whole greenhouse on a turntable because it is impractical to rotate the sun so I will rotate the plants instead ;)"

(Lermer) Perhaps this has escaped your attention, but the sun appears to move in the sky, from east to west. The sun is not on a light mover, the earth rotates around the sun. This changes the angles to compensate for shading of lower leaves.

    Bookmark   December 18, 2007 at 8:14PM
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One last LINK to illustrate what type of hard data I had in mind for this thread. So far I am finding that the aquarium community is much more ophisticated concerning aquatic plant lighting than the land gardening is about our plant lights. The challenge is on.

If there is not such hard data available on the narrow
product line I wanted discussed, then this thread will have reached its logical conclusion. Not every thread has to expand beyond it's premise.

I cannot help but post a swan song rant although is probably a waste of words. I originated this thread and was clear in my intial post that the thread should focus as much as possible on exchange of hard data. It obviously is seen as another battleground for debate (argument?) of the very same general issues found in a senior thread next door, by the same people I might add. Use links people! You fragment and dilute topical discussion in two if not more threads. If anyone cares, they will use the link.

Having posted this link and ranted, I'll humbly leave this knotted thread to its own devices. Perhaps we will meet again in my search for more disciplined forums.

    Bookmark   December 19, 2007 at 7:21PM
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The HPS reflectorized lamp costs only $60 from HTG supply. This is quite a bargain, considering how superior this style of lamp is, in my experience. Because the heat is not trapped inside of a reflector, the lamp can go closer to the plant, and really blast it with light. The shape of the reflector is designed by engineers, so that the element does not shade the reflected light, and the spread is remarkably uniform. DO NOT use it on seedlings or immature plants because it will bleach the h*ll out of them, but on mature flowering plants it is absolutely fantastic.
I just type the url using cut and paste where it says optional link URL, when I type my post:

    Bookmark   December 21, 2007 at 12:59AM
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Mind you, it is possible if you use just one lamp, way high up, so that the intensity on your seedling garden is only about 1000 footcandles, then possibly you could grow seedlings with this type of lamp too. Typically though it will provide
7000 - 10000 footcandles of intensity on your garden, just like blazing mid day equatorial sun. Possibly if your seedlings are six feet away from the lamps, they might be able to grow well. I generally start my seedlings under fluorescent, it's gentler, safer, and easier to handle. I just really haven't tried starting seeds with an HID, but my inclination for you would be to go with a 600W Metal Halide Conversion Lamp, and keep the lamp nice and high. HTG also sells economical lamps for this purpose, that put out good light and will definitely grow seedlings well. Just be sure to check the intensity if you have a meter. Seedlings only need about 1000 footcandles. If you notice the foliage going all yellow, then the light is too strong! Paul Mozarowski.

    Bookmark   December 21, 2007 at 1:17AM
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I notice the specs on that HTG lamp shows 72,000 lumens, and it's a 6000K lamp which means it will put out a fierce amount of blue, that will really stimulate chlorophyll production nicely, and get ur plants off to a good start. Like it says on their write up, HPS will produce stretched out and leggy seedlings, this lamp puts out tons of lumens, loads of blue, and it should do very nicely, compared to the expensive lamps you mentioned at the start of your thread. Plus, it has a 20,000 hour life span, but I would bank on replacing it at about half of its life, due to lumen degradation, although alternatively, you could just move the lamp closer to the seedlings to make up for the decreased output. This lamp goes for $55. cheap. They also sell the AgroMax conversion lamp; it has only 66,000 lumens, and it costs almost twice the cost of the Grow Brite lamp. I would buy the Grow Brite lamp. Maybe I even will buy it myself. I like the 600W level because it maximizes the lumens per watt, and my favourite lamp comes in that size as well.
Paul Mozarowski.

    Bookmark   December 21, 2007 at 1:28AM
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OK, thread regulars, I'm eating crow because I am back here posting to this thread. Several web searches have returned this thread so curiosity overcame. Object16, nice to see your last several posts. On target for what I wanted in this thread. I'm coming on board with you in that I'm drifting away from being 'hung up on it' but always enjoy playing detective on gadgets I'm buying. At least it's a more constructive pastime than watching TV right? :) Got a few weeks left before I gotta have bulb, so will hold off ordering while I explore more. This is a long post but maybe it will help someone. I'm giving lumens here only as point of product reference, not a claim that lumen numbers necessarily translate to a good number for comparing similar bulbs or better/worse performance for anyone's particular plants.

I'm definitely gonna go with at least one conversion bulb for one of the two bulbs for my seedling nursery. For second bulb choice I'm still comparing 400w MHs to 600w conversions. Yeh, conversions bulbs have less lumens and lifespan than MHs & PSMH but I can deal with that since I still get to use my HPS ballasts. Maybe a 600w CMH would come out by by time the conversion bulbs need replacing. Or something better?

object16; The GrowBright 600w MH conversion spec claims are very attractive so I'm been researching. Kinda dubious of claims. Web searches for that bulb and Growbright in general pull up a decent amount of forum hits. The Growbright claims of 72,000 lumnes and 20,000 hrs life are way above other MH conversions. ???? The 6000K is nice.
Also, I'm not an expert on spectral charts yet but HTG's page on the Growbright bulb has an insert image that has a
small spectral chart in it. You cannot read any axii number at all but the spectrum is suspcious. The blue end is very hard to believe.
hopefully this URL will bring up the insert image directly:
if not the parent page is:

"Growbright" searches brought a fair number of forum links. In the threads it was not uncommon to see comments that Growbright bulbs prematurely fail. Of course, since they claim 20,000 hours, I guess it is possible they still make it to the typical 9000-12000 hrs for other 600w MH conversions. Even if, still doesn't make it right to spec so high. I don't know a lot about electronics, but is there something that Growbright could have done with the bulb to push initial lumens high for it's type, but this has a downside of a higher premature failure rate?

SolarMax has a bulb SolarMax VEGETATIVE Conversion 600W MH. I'm very interested in this bulbs. Initial lumens 55,000 at 7200K and 9,000 hrs life. So far I'm leaning towards this one as a definite pick (1 of 2). One place $85, a second $84.
Good info page with images and a spectral chart. The blue-end performance is nice and much more believable than Growbright's chart.

Sunmaster has its Sunmaster 600 Watt Cool Deluxe MH Conversion Bulb: 50,000 lumens, 6000K and 10,000 hrs. Here's a URL to a distributor info page with images including a spectral chart. Not as good in the blue-end as the Solar Vegetation. Have found for $85 dollars.

object16, you say you like the Gavita reflector type bulb. You gave a link to their 600w HPS bulb. l had noted before
that, based on their light spread diagram, I estimated the bulb would spread light 5.5ft at 1 ft below the bulb, 11 ft across at 2ft. You say you have used the bulb, is this in line with what you saw?
At one point I got a nice spec/images page for a Reflux MH600 CD/E bulb off the Relighting web site, which was
supposed to be a MH conversion bulb. But as noted before, their website no longer supports English. Strange. I have
been unable to find another web link that speaks of this bulb. It may be that it is available overseas because Europe has Gavita bulbs not available here.

Lermer, I finally figured out what I think you meant for the spec table on the Life Light 's PSMH bulbs. Do you have any hard specs on the Sun Pulse HPS retro bulbs that you will share in this thread? The 6.4K and 10k are what I am esp interested in.

An off topic FYIs:
this site is to be highly commended because they give PPF (µmol/s-1) numbers for all their bulbs. The English site has more bulbs listed than the N.American.
this page has a chart showing three separate absorption curves for chlorophyll a, chloro b and carotenoid. Of course these are highly generalized curves, but it is one of very few charts I have encountered that showed that difference phothosynthetic pigments have different absorption curves. Handy chart to at least illustrate this to folks.

    Bookmark   December 23, 2007 at 12:41AM
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somehow I deleted a URL reference that was supposed to be above about the SolarMax Vegetation 600w MH Conversion. As noted it is good for info and has a spectral chart.

    Bookmark   December 23, 2007 at 12:47AM
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Hi, the Gavita light spreads very nicely, exactly as advertised. I was using it in a garden all lined by mylar, so the really widely spreading rays would bounce off the sides of the garden and illuminate the plant from the "wall side", that is the spread of the lamp made it so there wouldn't be hardly any shadows. I was using a 3 x 5 foot growing closet, and the gavita worked perfectly there. If you don't have a grow closet, then it would be good to hang a piece of plywood with mylar on it to refect the light going out sideways back into the garden.

    Bookmark   December 23, 2007 at 5:24AM
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It's possible there is bullsh*t on the grow bright lamp specs, but probably it is a very good lamp and they are just lying about it to sell more. But for that price, I would buy it.
Paul Mozarowski.

    Bookmark   December 23, 2007 at 5:28AM
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object16 is the web site. It looks probably like a prolific Chinese company flooding the market with cheap goods that probably work fairly well. The Chinese are fairly good at making knock offs, and they have a long history of culture and innovation, they graduate about 400,000 engineers per year, so I myself personally have a lot of respect for them.
They also have a history of lying about how good their products are, so if they exaggerate then this is par for the course, but I would expect at least their lamp is likely just as good as anything else on the market, just at half the price. I would at least try it, and check it with a digital light meter. Paul Mozarowski.

    Bookmark   December 23, 2007 at 5:38AM
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I've looked all around the net, and unless grow bright pulled off some kind of technological breakthrough, then their specs are probably all b.s. I would go to and buy an 850w pulse start metal halide kit for $85 for shipping and use a real pulse start metal halide lamp from them that has seriously good lumen output, has more lifespan than most MH lamps, with much better lumen maintenance. My own experience with conversion lamps is that they suck. The real metal halide works much better, and you'll be using a real lamp designed for that system. I presume that you don't smoke or drink or have any other vices, in which case you can justify blowing some small dollars on the real thing, and have something to admire. After all this is our hobby and we're allowed to spend some money on hobbies, as long as the purchase is prudent.
Paul Mozarowski.

    Bookmark   December 23, 2007 at 11:53AM
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Well I think I've finally made my decision for what to buy. (lol - Got about 1 more week before I need order bulbs so a change is always possible, but not likely.) I've been reading up on aquarium lighting. No disrespect to the many knowledgeable people within the gardening online community, but on the whole, the aquarium lighting community is way more sophisticated than the terrestrial plant lighting community. The sales market is pretty much like the plant market, doesn't provide much data and prices of bulbs similar but a little cheaper. But the user community never talks about lumens; they talk in terms of PPFD, which we know is the best photosynthesis related unit of light measurement.

I'm going to start a new thread about the great data you can get through the aquarium community and raise the question of why can't the land gardeners do the same. I'll leave my discussion of their data to the new thread so let's meet there if you interested in that.

Aquarium folks like high color temps, so for HID, they use metal halides, probe and start. So you can find lots of great info on MH but essentially none on HPS or conversion bulbs. Some aquarium experts have generated spectral data for 900+ bulbs and it can be accessed through a site I'm naming over in the new thread. They have also written bulb comparison articles based on the same data.
Based on their data I've decided to get two EVC (brand) 400W 10000K probe start metal halide bulbs ($57 ea), which run optimally on a M59 type ballast. The EVC bulb gets a very good PPFD (205 umol/m2/s) and a broad spectrum on the blue end (remember I'm focusing on vegetative growth). I'm going to get Magnetek M59 ballast kits ($83ea) because that was the one used for the testing of that bulb, although several folks said any ol' m59 should work fine.

I'll gut one of my Sun System I housings and install a new ballast kit. Since probe start doesn't require an ignitor, things will be easier for me as a very novice electrical guy. I could have gotten slightly higher PPFD's with a few other bulbs but you had to start getting into HQI ballasts which cost a lot more. The second EVC bulb & ballast I'm going to install in my Sun System II fixture (self-contained). Thought about getting a 250W bulb instead of second 400w but decided against that. If I was going to get a 250w I would have gone with the XM 250w 10000K probe start MH and a M58 ballast.

I will be starting seeds all along so by April my plant area might be too big for the two 400'ers to cover. If so, I'll kick in my spare 600W Super Hortilux system to get me to frost free outdoor conditions. Might even do that anyways if some plants look like they would benefit by more red light. If you match up the spectral curves of the EVC MH and the Hortilux Super HPS, you'd see that the combined light makes for a decent full spectrum although a bit weak in the desirable 640 nm peak area. Other HPS bulbs could do better I'm sure. A combo with the Philips Mastercolor 400w CMH HPS-retro might be a really nice full spectrum.

I know the MH bulbs have shorter lifes and are less PAR/watt efficient than HPS, but that is just the cost of business to do what I want to do. If in the future suitable 600W HPS S106 compatible bulbs come along, I can put my old ballasts back in. I stopped considering the reg terrestrial plant-light bulbs because I could not get good data on them. I have more comments along that line which I'm going note in the new thread.

    Bookmark   December 28, 2007 at 11:48PM
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shrubs_n_bulbs(z8/9 UK)

PPFD, which we know is the best photosynthesis related unit of light measurement
It isn't. However it is better than lumens. On the downside nobody provides standardised figures for their products in terms of photon flux so 90% of what you read about it is BS or endless arguments about which spectrum provides the best PPFD. This of course is no different from endless arguments in this forum about which spectrum provides the best performance, they just use more sophisticated terminology to blind you with their vast knowledge ;) For every calculation of PPFD, you can make a different calculation of a photo flux actually weighted to match the photosynthesis action spectrum (you will find some of these calculations online also, I have linked to one of them). And a different calculation for the precise spectrum of every different plant species. Do not be blinded by a calculation showing one lamp to be 10% better than another, a different calculation by a different person or for a different plant would show the opposite result.

Aquarium folks like high color temps
D'oh!!! I see you, and possibly the people you have been reading, have missed a very important point. They are growing in water. Therefore blue light is relatively more important. Growing in saltwater, that is doubly or triply true. Algae have a radically different action spectrum from terrestrial plants. Coral growers deliberately choose lights with a high UV component to increase fluorescence in their babies, not necessarily needed for growth but it makes them nicer to look at. If you plan to grow in air and not to grow coral or algae, then you don't necessarily need the same lights.

high color temps, so for HID, they use metal halides
What an astonoshing statement. Typical metal halides have the same colour temperature as a cool white fluorescent. Possibly you have mis-read the aquarium community. The sort of lights they like are blue actinics and those mega-high colour temperature lights where the actual number is almost irrelevant, but anyway they are all blue and no red. These are frequently now the power compact fluorescents because of the UV and blue spectrums they can provide, but also ultra-high colour temperature metal halides are used, not at all the same as you would choose for growing terrestrial plants. See comments above about water and coral, you do not want to use these lights on your plants.

I feel you have made very poor choices in your plant lights, presumably based on poor advice. For example, probe start on a magnetic ballast is simply the wrong answer, always, there is just no excuse for buying such a system today. I will make the guess that you have also been reading extremely in-depth studies but rather out of date and so are choosing obsolete equipment based on recommendations made 5 or 10 years ago. Or perhaps on "accepted wisdom" handed down from 10 or 20 years ago.

    Bookmark   December 29, 2007 at 6:58AM
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The aquarium growers are GROWING IN WATER, and they need the high blue content to penetrate into their aquarium. You have made A TERRIBLE CHOICE OF LAMPS, COULD NOT BE ANY WORSE!!!
Just look at the photosynthetic action spectrum and quickly realize that LIGHT COLOR IS NOT THE MAGIC, ALL LIGHT PHOTONS WORK JUST ABOUT THE SAME, and lux just happens to be a rough but very useful measurement. Use pulse start metal halide lamps, $30 apiece for the 400W lamp at to provide your plants with plenty of blue light that it needs to make chlorophyll, lots of green and yellow to provide photons for photosynthesis via the carotenoid accessory pigment, and enough red to keep everything happy!!! Lumen Labs has a sale on now for 400W electronic ballasts that will fire up a pulse start lamp nicely, I emailed them myself to make sure. Then get urself some nice Gavita 600W HPS lamps to flood your garden with photons once the seedlings are a good size. This is what I do myself, and the growth is AWESOME AND PHENOMENAL!!! There is no difference in my grow, and what you would find in a wide open farmer's field growing a fine crop under ideal conditions in fertile soil.

Besides looking up the link below, also check Berkeley University edu site for information of photosynthesis and plant pigment, and FOR GAWDS SAKE DO NOT BUY PROBE START 10000K lamps - THAT'S FOR AQUARIUM USE!!! Paul Mozarowski.

    Bookmark   December 29, 2007 at 10:36PM
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Seedlings don't need very intense light, just a 400W pulse start halide will give it lots of blue and violet to get it producing chlorophyll like mad, then add the reflectorized HPS lamp to stimulate growth like you won't believe.
When light goes through water, it scatters like mad, so only the very short wavelengths will penetrate, the rest is all scattered off, that's why our sky looks blue, but the sunset is red, scatter is proportional to wavelength, but in water scatter is a very serious problem, so the must use 10000K to 20000K lamps to overcome this. We're land farmers, so we use land farmer lamps.
Paul Mozarowski.

    Bookmark   December 29, 2007 at 10:43PM
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Unfortunately the owners of were also in the seed selling business and their servers were seized and they were locked down by p*gs. All of the most important recent growing information went down with it, along with a very active and knowledgeable growing community. Unfortunately this forum does not have the activity of the overgrow site, and you're not able to get the real growing advice from actual growers that have been forced underground by p*gs. some of the faq of the overgrow site was rescued by grasscity, and you might be able to find advice on the types of forums, whose mission is to grow the most amount of weed in the least amount of space. And by mission, I mean mission. These people are serious, and results are measured in grams, and guaged and discussed over a bowlful, and the results measured by bio-assay (quality and type of high).
I am an orphan of that community, but my advice is that ur headed in the wrong direction, take a bit more time, or even before doing anything rash, just use a plain old halide conversion lamp from HTG, set it up with a decent reflector, use plenty of mylar, and you'll be in business. Or if you're going with a dedicated halide, use pulse start, pulse start lamps can be run continuously for 30,000 hours and still be useable for growing. Electronic ballast is very gentle on them, and these lamps have terrific lumen maintenance. Regular 4000K lamps are fine for land farmers.
Paul Mozarowski.

    Bookmark   December 30, 2007 at 1:28AM
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follow link to, not as experienced as overgrow, but it's all we have left

    Bookmark   December 30, 2007 at 4:53AM
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Alway important to remember the words of the great ones:
"I can envisage a new world in which society has a way for there to be music, whose function is to get you high, that's the sort of thing we're hammering at. To get really high is to forget yourself; and to forget yourself is to see everything else; and to see everything else is to become an understanding molecule in evolution, a conscious tool of the universe. That's why I thimk it's important to get high." Jerry Garcia.

    Bookmark   December 30, 2007 at 5:08AM
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